Grafting 67/68 Shock Towers To 65/66 Mustang

Thank You Rusty.

I also wanted to point out that in addition to the FE and Lima motors I mentioned above, a 351C would be right at home in the new engine bay using any off the shelf header spec'ed for a 70' Mustang. Although this has been done previously using specific and perhaps costly "swap" headers, the added clearance given by the later shock towers offers ample room to work on the motor.

In this post I'll detail how I notched the 67/68' shock towers.

I used a discarded pair of 65' Mustsang coil springs to help determine the amount of spring-to-shock tower clearance before doing any cutting of the tower. One full coil was cut off of one spring so it could be positioned by hand:



The spring was at its closest when the UCA is extended and resting on the frame (its full downward location.) The closest point was located just above the LCA pivot where I measured 3" to the tower.

The 2nd spring had 3 coils cut off. It was installed using blocks to hold the UCA upward firmly against the bumpstop:





IIRC, there was 3/4" of free space at the top of the tower. With that info, I felt confident in doing some cutting.

From the beginning, I didn't want to do the typical press brake type 90* flat plate notch that is so often done. At the very minimal, I wanted the angle change above the UCA to be rounded. Also I wanted the plateau over the 2 UCA to angle slightly downward toward the engine compartment. None of the local machine shops had the dies to create a quickly rounded 70*-90* angle so instead I had them do something a little different. Basically 2 press brake bends (20* and 70*) 5" apart on a pair of 13"x16" sections of 1/8" (11ga) sheet metal. There was also to be some rounding on the 5" center section between the bends. Here is what they came up with:





When I compared the plates to the shock towers I really didn't like this 2 bend design as much as I had hoped and ended up trashing the idea. Since I originally had my heart set on a rounded angle, I got creative. With a quick trip to the nearest scrap yard I picked up a suitable length of thick walled 4" square tubing that had rounded corners to use as a jig pattern:







OK, maybe I went overboard on the length, but it was cheaper (and faster) to take the whole 6' section rather than have them cut it shorter. Perhaps it may be used for some other project in the future.

I began by marking the bend location on a 1' square piece of 3/16" plate steel:



This plate was clamped to the square tubing, sandwiched with a separate 1/4" plate on top to help hold the 3/16" plate firmly in place. The marked line is placed parallel with the bend on the square tubing:



The lined area of the plate was heated cherry red with a cutting torch and then bent with several strikes from a decent sized hammer:





This is not a fast procedure as it required several minutes to heat the metal hot enough to bend the plate. All that metal literally sucked up the torch heat in an effort to dissapate it. Still, the result was good and it gave me the nice clean rounded bends that I desired:





I was then ready to notch the shock tower. It was cut using the same techniques that others have documented in the past, such as in this thread: http://www.fordmuscleforums.com/suspension-articles/498392-notching-shock-towers.html

First the shock towers were covered with masking tape in order to make it easier to make cutting lines:



1/8" holes were drilled to verify some locations and to act as a guide. The first cut was inward 1/2" at the top of the tower, 2 1/4" at the bottom, and a horizontal cut was made 1 1/4" above the UCA pivot bolt holes. Both a saws-all and an angle grinder were used to remove the center section of the tower:









Its hard to tell, but the lower cut was done on a downward angle toward the engine compartment.

I was not yet satisfied with the rounded bend design as it looked out of character being so darn flat above the bend. I stared at the A shaped piece that I had just cut out and wondered if I could incorporate some of it into the design, specifically the upright rounded corners where the tower meets the new sheet metal insert. I did a little hacking on the A shaped piece and saw that my idea had merit. After a little more trimming with the saws-all and grinder I came up with a solution that I haven't seen done before:

Now all I needed was a way to support the A shaped section. I experimented with a piece of cardboard and found that the formed 3/16" sheet metal plates could be used as a backing:







This is what the trimmed backing plate ended up looking like:



Here is the final design of the backing plate being tacked to the tower:



The A shaped section will be inserted between the metal plate and the shock tower uprights. This allows for welding on both the inside and outside of the shock tower.

Before attaching the A shaped section, I cut the towers back a little more from the midpoint to the bottom. The gap shown is needed so that the A shaped section can sit flat against the metal plate.:



The shock tower plate needed sectioned to help it better conform to the other parts:



The A shaped section was then tacked into place after a little heating and bending of the cut towers so that the rounded contours matched:





Here's what the finished shock towers will look like:







Comparison photo:



Wheel side of the tower:



Some photos of the driver's side getting the same treatment:

















Here is where I stopped at the end of the weekend:



The notch gives an additional 1 3/4" of clearance per side at the raised areas of the A shaped section and 2 1/4" clearance in the gap between those 2 areas. There is now a finger thickness (about 1/2") clearance between the coil spring and the notched shock tower.

The worst is pretty much out of the way now. I found that adding the A shaped part of the shock tower required lots of grinding and fitting. The basic process is easy, but unfortunately it's taking much more time to accomplish than I had originally anticipated. I do love the look over the typical flat side notch so its still a worthwhile endeavor to me.

Made some progress on the welding front. Finished the rough installation of the driver's side tower:













Made, fitted, and added the big block tower supports. Used 3/16" steel plate:





Lots of filler welding and grinding to make the tower edges smooth:













Rear of towers get BB supports and detailed too:





About all that is left before primer is to grind the welds around the inside of the A shaped piece and to make the 4 UCA frame supports. Very little body filler will be needed before its put into paint. The majority of that on the aprons.

Thanks Jim. It's coming along as good as I could ever hope for. Should be in primer after the next go round.

Finally some noticeable progress.

Made some additional supports for the tower and welded them in:





Essentially I have built and added every part of this kit:



Finished sanding the electrocoat off the towers:









Added a skim coat of body filler to the panels where needed:





Sanded the filler until it was smooth:





That was the worst 2 hours of work of the whole shock tower grafting job . . . . . .

Gave the bare spots 2 coats of epoxy primer and followed that up with seam sealer:

















Once that set up, I then hit the engine compartment side of the towers with 4 coats of epoxy surfacer:

The primer finally allows you to see the A frame part of the towers that I worked so hard on:





On the wheel well side of the towers and under the frame I used black brush-on Rustoleum (my favorite low-buck rust preventer):











The next time that I am in the garage I'll undercoat the wheel wells, plus sand and paint the engine compartment. Possible get the suspension installed too.

Billm said:

Dennis nice project. It would be nice to have all of that room for a small block! Can't wait to see photos of the engine installed.

Click to expand...

Thanks Bill. Its been an interesting and fun project. I hope to have it wrapped up by this time next month just in time for the racing season.

Below are some measurements between my notched shock towers.



From top to the bottom on the above photo,

1. Top of shock towers is 28 5/8"
2. Deep part between the" "A" shaped sections is 30"
3. "A" shaped protrusion just above the shelf is also 28 5/8"
4. The innermost part of the shelf is 25 1/2"

I wasn't feeling up to par over the weekend but did get a little bit done after cleaning up the dusty and dirty garage.

Sanded and spray bombed the engine compartment semi-gloss black:











Note in the following photo that I previously grafted a 67/68 radiator support in order to use the 24" wide radiator:





Installed the front suspension and steering box. Also reused my old 65' KH 4 piston disc brakes:



67/68' UCA's:





I reused my old roller spring perches which is compatible with the 67/68' UCA's.

67/68' spring cover installed over the Moog 8306 6 cylinder coil spring:



I was surprised that the 67/68' UCA's do not touch the frame when the spindle/LCA are installed like they do on every 65/66' that I have owned:





You can also see the rubber plugs I used in the Trans Am shock tower brace after adding rust protection.

67/68' LCA and strut rods:





67/68' steering center link and inner tie rod ends:



Not shown are the 65/66' outer tire rod ends that are required to match the 65/66' spindle. The 67' and newer stuff will not work unless you are using the later spindles.

67/68' idler arm used the same holes as the 65/66's:





67' specific 1" shaft manual steering pitman arm installed on the 65' steering box:



All bare parts will be painted black (as that's the way I roll.) There are also some areas that need to be touched up.

Currently trying to get a handle on the motor mount situation. Unfortunately the original 65' 3 piece stud mount cannot be used on the newer shock tower motor supports. I also found that the later 66+ frame mount with the specified Anchor 2257 rubber insulator motor mounts will place the motor at least 1/2" higher in the engine bay--UNACCEPTABLE for hood clearance and for racing. I previously tried a set of Ron Morris adjustable mounts and my current headers interfered badly on the driver's side. Since I need to reuse the headers again this year, I need to find another suitable solution that lowers the motor.

Here are the original 65' 3 pc mounts:



66-70 frame mount and the typical 66+ Mustang specific mount (Anchor 2257):





Note how tall the upper arms are on the rubber mount where it would attach to the block. I have ordered a couple of other types of mounts (2244 & 2287) with shorter arms to see if they can be used instead. I have heard of people using the 2287 so there is some hope there. I'll update my findings later.

Finally solved the motor mount problem.

I tried various Ford type lowered rubber motor mounts and had zero luck making them work with the 66'+ type shock tower brackets. The 2244 & 2287 that I ordered were not close enough of a fit for me (actually both look like the same mount.) I thought of making a pair of 65' style shock tower frame brackets to reinstall the 65' rubber mounts, but it seemed quite stupid to spend the time to reinstall something that was marginal in a drag capacity and certain to fail with the future head upgrade. Since I knew I was going to end up fabricating something, I decided to purchase another set of Ron Morris motor mounts and see what it would take to make them work with my present combo. Back in 09' I had a set and at that time decided that the same Accufab 1 3/4" headers that are in use today would not work with the RM mounts so I sold them here on Stangnet.

The passenger side header did not cause any interference with the RM mount:



The same could not be said about the driver's side:



Note how the tubes drop below each other. #5 tube on the bottom wanted more than its share of the space that the RM mount needed. The RM engine mount wouldn't work because the adjustable feature of the RM engine bracket extents quite away from the block. Even my old 65' mounts required some trimming for the same header tube.

The offending part:



Like they say, necessity is the mother of invention.

I ordered the Ron Morris 1/2" drop mounts from CJ Pony parts since they are close and they were in stock. Unfortunately even after telling them 3 times that I wanted the lowered version they sent the standard height mounts. It took a week to get them replaced so I lost valuable time.

The RM mounts are the cross bolt type and are very well made. Here are some photos of the first set of RM mounts I received:









Once I received the proper 1/2" drop mounts I set to work adapting them to my motor. While the motor was on the stand I bolted the headers on to test the clearance of the RM mounts. Just as I had remembered, the passenger side cleared nicely and there was no issues there. On the other hand the driver's side was a no-go due to the width of the adjustable block mount. The first part of my solution was to build a taller and narrower block mount. I ended up stacking a 1 1/2" x 1/2" piece of metal strapping on top of a 1 1/2" x 3/8" piece of strapping and using longer bolts to sandwich them to the block. Here is an "in process" photo of the original RM block mount and the new ones being made:



Once I was satisfied with the fit on the engine stand, it was time to install the motor and verify my idea. Here is a photo of the passenger side RM mount installed without the headers:



The driver's side mount required more fabrication in order to use the RM bushing. The narrower block mount t that I made required a longer pair of replacement "wing" brackets be built for the shock tower brace. The wing brackets also needed an additional drop to accommodate the 1/2" thicker block mount. Here are the 1/2" drop RM shock tower frame brackets and my nearly 1" drop homemade brackets:



Some testing of the shock tower frame brackets:









I ended up with almost 1/4" of clearance to the bottom of the lowest header tube.

Once I was satisfied with the fit, I removed and slotted the homemade brackets to get the same adjustability as the original RM brackets. Everything was then cleaned up and painted black.

Much to my surprise I am now able to install the Accufab 1 3/4" headers from the underside of the car without unbolting the motor or the transmission from the mounts. All it took was some careful maneuvering in order to clear the motor, scattershield, and the shock towers. I've never installed the headers so easily on this car without the use of the engine hoist and a little cussing! Even the Z-bar that I hated to install was a breeze because the headers had much more room to be moved out of the way.

Here are the photos that followers of this thread have been waiting for!

Driver's side BEFORE the shock tower mod:







Driver's side AFTER the shock tower mod:









Passenger side BEFORE the shock tower mod:







Passenger side AFTER the shock tower mod:









(Remember that this is a 351w based motor with 1 3/4" headers)

Currently reinstalling all the body parts that were removed and getting the motor ready to be fired up in time for the first race of the season. More photos and thoughts to come.

lord_cobra said:

What a difference! I don't even need the extra room on my 69 but still wouldn't mind doing something similar

Click to expand...

You can't imagine how easy it is to change spark plugs now. I can use a socket and ratchet on 6 plugs--the other 2 can't be done that way because the tubes of the headers are in their own way.