Increasing Engine Setback

67Sally

Founding Member
Jun 24, 2002
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I would like to talk to anyone who has experience with increasing the engine setback on a classic mustang. My project is a '67 fastback and I am exploring options of moving the FE390 rearward for better weight balance.
 
Anything is possible if you have the money, tools, skill, and determination. It will require major firewall surgery which could negate some of the conveniences like A/C, heater, radio, etc.
You might find it cheaper and for sure easier to get aluminum heads and intake to reduce the weight of the engine.
Howard :shrug:
 
I'm running 3" setback on my 302 engined '65, here's a few things to look out for:

1. sump and pickup may/will need to be modified to clear steering gear and crossmember. (remember if you do move the engine back to check the steering on full lock as the inside ball joints might hit the sump as mine did before i switched to a rack)
2. engine and gearbox mounts/crossmembers will need fabbing/modifying. (I threw out the original mustang 'pipe' crossmember and fabbed an RHS crossmember that also takes the engine mounts. It bolts to the original crossmember mount and to the original engine mount on the tower. Gearbox mount is on 'sliding' rails to accomodate the different lengths of the gearboxes that might find their way into the car)
3. shortened tailshaft.
4. Make sure the engine maintains its 4 degree inclination!
5. At 3" setback, I can still get the heads off with the engine in the car. As I have remade the firewall to suit the RHD conversion, I think I might have a bit more 'setback room' than a standard Mustang.

As I've made it possible to fit either a toploader, tremec or c4 without any further mods I also had to re-fab the transmission tunnel. This might interfere with the standard heater/blower unit, i'm not sure.

Possibly, you might come into trouble with the clutch release or auto trans linkages as the tunnel narrows to the rear. I'm using a hydraulic throwout bearing so bellhousing/firewall clearance can be kept to a minimum.

Anything to get the driveline weight further rearwards will help. You'l notice the difference even more if you can get some aluminium on the engine.
 
1970 slantroof said:
Anything is possible if you have the money, tools, skill, and determination. It will require major firewall surgery which could negate some of the conveniences like A/C, heater, radio, etc.
You might find it cheaper and for sure easier to get aluminum heads and intake to reduce the weight of the engine.
Howard :shrug:

:rolleyes:
67Sally said:
I would like to talk to anyone who has experience with increasing the engine setback on a classic mustang. My project is a '67 fastback and I am exploring options of moving the FE390 rearward for better weight balance.

1. The Professor took some measurements of his '67 390GT and feels that there is 2.5 to 3 inches to play with before firewall surgery is required.

2. If I take the fire wall surgery route and go for a 6 inch set back:
- A/C will be taken care of with a Vintage Air unit.
- Heater won't be an issue as the stang is in the garage during the Chicago winters.
- Radio won't be an issue unless I go back more than 6 inches, in which there will be bigger issues than the radio location.

3. As for the aluminum I think that I have that covered.......and then some maybe.

4. Howard the :rolleyes: at the begining of the reply was just a joke. I figured that I would have a whole slew of people throwing SuperDaves wisdom at me. You have brought up some good points to remember.

gp001 said:
What in the heck are you planning William? How much do you want to go back? Are you looking to go lower as well?

1. :D uhh :D uhh :D I'd tell you Dwain but then I might have to share my football...... :rlaugh:. Actually I figured I do a cannonball run out to cali and hit a canyon or two with the gp crew and get a membership number. But this may take some time as I am now just getting everything tore down in preparation for the trip to paint stripper before the end of the month. The plan is to have a clean platform to begin my psyco modificataions by February at which time progress has a high probibality of slowing down....wait I forgot to tell you guys that my wife and I expecting a baby boy and the due date is Feb 6, 2004.

2. I am exploring two options: a) w/o firewall surgery, b) w/ surgery

3. The suspension will be lower than stock. I have adjustable coil overs in the front and rear now.

ozstang65 said:
I'm running 3" setback on my 302 engined '65, here's a few things to look out for:

1. I am running a rack n pinion steering too.
2. This interests me and I would like to see any pictures you have. Where are you located. I typically make it to the land down under about once every year or two with work.
3. I hadn't given any thought to the tail shaft....thanks. I will be running a ROD 6 speed and figure that if the shifter ends up a little further back it will be ok and if it is too far back I could always incorporate the shelby trick that he used in his cobras. I already am planning on using an aluminum drive shaft and the ROD will necessate a custom drive shaft already.
4. Yes, I plan on keeping the engine degree the same.
5. As noted earlier I will be running the ROD and Dwain tells me that it fits with minor hammer work.
6. I am going to run a hydrolic clutch and Dwain has me covered there too.
7. As for the aluminum I am running aluminum: heads, intake, water pump, air cleaner, and oil pan.
 
I'm near to Brisbane in the land of Oz, I don't have any of my car pics here at work so I'll have to get back to you on the crossmembers when i look thru my archive. I'm actually taking the digital camera home from work now to get some latest pics so i'll post the relevant one's a bit later.
 
Sorry to steal your post, but I have a little question conserning engine inclination degree. I have -66 coupe with 351 and Toploader. I installed 351 with modified 289 enginemounts, placing engine 1" lower than original. I´m using original gearbox crossmember. This changes engines angle a little, should I be concerned, and do something to it? I could lower the gearbox-end a little?

I calculated that angle is now closer 2 degrees... ?
 
67sally--- Having owned a big block Stang and while not having run it on a road course, but on the back roads around where I live, I think that just moving the motor back 2-3 inches isn't going to improve the handling much more than what mods you've already done. It's more likely to cause you more headaches than benefits. I've driven various vehicles for a living for 25 years now, and can truthfully say this, practice makes perfect. You'd do better to spend your time by driving the car more than spending $$ and effort moving the engine back. Has your list of mods included moving the battery to the trunk? How about an aluminum radiator? A larger fuel tank would also help with the weight differential and help out your long distance plans. But then again it's your car.
 
67Sally said:
1. :D uhh :D uhh :D I'd tell you Dwain but then I might have to share my football...... :rlaugh:. Actually I figured I do a cannonball run out to cali and hit a canyon or two with the gp crew and get a membership number. But this may take some time as I am now just getting everything tore down in preparation for the trip to paint stripper before the end of the month. The plan is to have a clean platform to begin my psyco modificataions by February at which time progress has a high probibality of slowing down....wait I forgot to tell you guys that my wife and I expecting a baby boy and the due date is Feb 6, 2004.

First off, Congrats on the 2004 model baby boy. I hope you and your wife have an easy, problem free delivery.

You can be an honorary gp & 2mff member. How bout gpwilly? :rlaugh: :rlaugh:

As for you trans issues you should actually be better off. If it sits a few inches back the shift rods may clear without touching the trans tunnel crossmember at all. That was the only thing I needed clearancing for. Also, you might be better off in terms of the shifter as well. The shifter I had to use has a pretty significant bend toward the rear. My seats do sit a little farther back, but having the shifter back farther a few inches would be great. Especially if some monkey designs a sequential shifter setup for the ROD (wink, wink, nod, nod). Then the short, striaght shifter that comes with the ROD would work great.

int1a02.JPG
 
ozstang65 said:
I am looking forward to seeing the pictures.

D.Hearne said:
I have moved the battery to the trunk and will upgrade to an aluminum radiator before everything is done.

HistoricMustang said:
I will have to check out the vintage races. I know that they take place at Road America.

gp001 said:
The sequencial shifter has and is something that continues to give me shifter envy every time you bring it up.
 
67Sally said:
The sequencial shifter has and is something that continues to give me shifter envy every time you bring it up.

Maybe by the time you are ready to shift that thing one might be headed your way. IF I can get the friggin guy to cnc the lobes and gears I need for the prototype. If not I'm gonna rough cut them out of acrylic and start the testing of the prototype.
 
Sorry about the delay, got sidetracked and put back a weekend. The pics I have linked here are from my setup. If you think the pics don't look like a Mustang, I can assure you they are of my '65! The towers have been replaced with EB Falcon towers which allow me to use a SLALS suspension setup (similar to the current T-Bird). The only original bits that remain are the base of the original towers (engine mounts) and the lower arm attachment points.

Pic 1 - This is a local Falcon engine mount, I'm not sure if there's an equivalent in the US, maybe from a Ranchero, Falcon or something similar.

img_0004.jpg


Pic 2 - I can't remember if this is the exact location of the original x-member mounting, but it's pretty close. The chassis rail has been tubed, the bolt goes through from the bottom and there is a plated nut which goes onto the top of the old chassis rails (within the new tower base and out of sight).

img_0018.jpg


Pic 3 - x-member in place.

img_0030.jpg


Pic 4 & 5 show the logditudinal attachment to the original engine mount hole.

img_0031.jpg


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Pic 6 - With the Power rack installed.

img_0033.jpg


As you can see, some of the components are still at mock-up stage. If you're wondering, the sway bar is held in place by the rack mounts.

Scott
 
ozstang65 said:
The towers have been replaced with EB Falcon towers which allow me to use a SLALS suspension setup (similar to the current T-Bird).

!!! do you have any pics of your completed setup? what kind of car is it out of exactly? :nice:
 
kslushy said:
!!! do you have any pics of your completed setup? what kind of car is it out of exactly? :nice:

No, those photos were only taken yesterday, it's still very much a work in progress! The front suspension is taken from an E-series Australian Falcon (1988-'98 or thereabouts) similar to my daily driver :
img_0038.jpg

(dime a dozen in the wrecking yards out here)

The rack is supplied by RRS in Sydney and the swaybar will be custom made.