There’s a good chance he will still beat me with that stroked 408 with a tremec and me stuck with my C4 slipping. But at least I’ll look cool in the losers circle.
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351 Cleveland swapped MII
- Thread starter 78 Mach1
- Start date
Blackhawkxx
Advanced Member
- Mar 3, 2023
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Did it carburate well out of the box with the tunnel ram or did it take some tuning? Also, it's time for a cam to let that thing breath a little.Took the car to a local car show just to get out of the house. On the way home, my son pulled up next to me in his 73 Mach 1. He walked away from me pretty easily. Now, in my defense, he has a 351 stroked to a 408 and a tremec 5 speed. But none the less, I would have preferred it to be a little closer. lol. So I decided it was time to lose the two barrel carburetor.
I installed the tunnel ram, a Holley 650 double pumper, Redhorse fuel pressure regulator, and full return style full system. I was originally deadheaded. The return style will better regulate fuel pressure as well as provide consistently cooler fuel to the carb.
Here’s how she sits now.
It started and idled with no issues. The carb is one I had sitting on the shelf for around 5 years. The rear needle seat needed a new oring. But other than that, the carb was surprisingly good still. I had to set float levels of course. I do believe I need to jet it up. I had to set the accelerator pump to squirt earlier and I’m thinking larger squirters will be necessary under load but it revs good in park. Haven’t been able to drive it yet because my throttle cable is too short. I ordered a generic cable and a carb base mounted throttle bracket. As soon as I get that, I’ll be able to see what the drivability is like.
A cam is on the list of things to do this winter. But I just want to enjoy it for now while the weather is cooperating.
I believe you are correct. I’m going to try and jet up the 650 as well as increase the accelerator pump flow. This is a temporary carb so I can enjoy it before the weather turns bad. Then a cam and new carb will come. Probably a 750 mechanical secondary to help prevent lean conditions in the rear cylinders.
Still not sure about the head flow. I haven’t had a chance to get it on the road and test it under load. So we will see soon enough. I don’t think head flow will be an issue. I’m more concerned about getting enough fuel to prevent from leaning out the rear cylinders.
I do have a set of quench 4v heads if the heads end up being an issue. But honestly, I do not believe they will. I’m actually thinking the higher velocity of the smaller port 2v heads will help the tunnel ram on the road. Even 2v Cleveland head ports are larger than most factory and even aftermarket heads.
I need a set of upper rear shock mounts for a Mustang II? Anyone know where I can get a set? I somehow misplaced mine over the years. Or accidentally threw them away with the old shocks. Who knows. I found a set locally for $100. But that seemed high for such a small piece. I was hoping someone made some aftermarket. But I can’t find any. So my next option is to find someone that has a set on a parts car they wouldn’t mind letting go.
No. I need the rear shock mounts. There’s a plate that the top of the shock bolts to. Then that plate bolts to the body with three bolts to hold the top of the rear shock in place.
I found this picture on line. That metal bracket the shock is bolted to is what I’m missing. There is one on both sides top of the rear shock. I believe they are a Mustang II only part.
If I don’t find anything, I can make a set. But I honestly would rather grab a set from a parts car so I can have shocks for my first test drive with the tunnel ram. Rear gets pretty bouncy without them.
Totally off topic. But I have to give my 1976 Cobra II some love. The starter is having issues. It’s a 302 4 speed car.
I put this motor in this car, but I obviously installed the motor with the starter in place. Does anyone have any secrets to getting this starter out without raising the motor? I’m considering dropping the steering rack.
Well yes, yes I do.... 
stangnet.com
It's in the tech sticky at the top of the II home page. It's really not all that bad once you get into it.
Oil pan gasket change OR starter replacement in a 302 II
Here's a quick how-to on changing an oil pan gasket on a 302 without removing the engine. It's the same steps as changing a starter more or less, so it's basically 2 birds with 1 stone. First, raise the car to an appropriate height and support it. Remove the (-) battery cable from the battery...
stangnet.com
It's in the tech sticky at the top of the II home page. It's really not all that bad once you get into it.
It's not just you my friend. Gremlins [hate] the sound of a toolbox opening. It makes them crazy.
I ended buying a full set top and bottom mounting plates for the rear shocks. They also came with a good set of shocks. That worked out perfectly. I’ve been focusing the past several days dialing in the carburetor. I had a hesitation when accelerating. I put a different accelerator pump cam on both ends and that fixed the issue. I went with the orange cam which gave me a more aggressive profile to get more fuel faster. The car runs really good now. But I do believe I need to jet it up still. No real evidence other than seat of pants feel. It’s a Proform 650 street series carburetor. Currently has 73 jest in front and 74 jets in rear. I believe that is a little small for this large plenum tunnel ram. So I’ll be testing some larger ones when I get my jet kit in. What I couldn’t find anywhere is if these jets that are currently in there are the correct size for this carburetor. I’m trying to figure what it came with from the OEM. I got this carb used. So anything is possible. My belief is someone had it in a very mild small block. Because the accelerator pump cam was very small. And I believe these jets are pretty small comparatively. Does anyone have any information on what jets this carb originally would have had? Also does anyone have any experience with a good starting point in jet size for a 351 Cleveland with a large intake plenum? I know jet sizing is a trial and error thing. But I’d like a good starting point if possible.
I can't say for sure what that specific carb came with for stock jets, but here's what the Holley book that I have said about my double pumper. Maybe it'll give you a rough starting point?
If you need, I can pull that book out when I get home from work (about 4 hours from now....) and get some other numbers for you. You can kinda see the numbers below the section of the book I shared here:Stock specs for this particular carburetor.
85GTStangGuy
5 Year Member
The Proform site shows the 650 cfm street series carb as having "Primary Main Jet Size 86/93". No mention of secondary jet size, unless that's what the 93 indicates.
Engine Carburetor; Street Series Model; 650 CFM; Mechanical Secondaries Type | #67212
PROFORM's new Street Series Carburetors are hand assembled in the U.S. Based on the wildly successful Race Series carburetors the new PROFORM street carburetors. Constructed of light weight aluminum, changeable idle air bleeds for easy non-permanent calibration changes if needed. Fine tuning is...
www.proformparts.com
Blackhawkxx
Advanced Member
- Mar 3, 2023
- 465
- 462
- 73
I have played with a lot of 4150 style Holley and Demon carbs and the standard I've seen is about 70 front and 76 rear in stock form. Proform may have their own jet numbering? 86/93 in Holley terms is huge for a 650.
I agree. 86/93 seems really big. I currently have 73/74. I thought I was experiencing a lean issue. But the plugs show something different. They look slightly rich to me. Well, one side at least.
This is the same plug just spun 180. One side looks rich and the other looks lean. Not sure what that’s about.
However, I did just discover tranny fluid in my vacuum line. Only one place that can be coming from. The vacuum modulator. So I probably have a vacuum leak there. I need to sort that out before any further carb adjustments.
This is the same plug just spun 180. One side looks rich and the other looks lean. Not sure what that’s about.
However, I did just discover tranny fluid in my vacuum line. Only one place that can be coming from. The vacuum modulator. So I probably have a vacuum leak there. I need to sort that out before any further carb adjustments.
85GTStangGuy
5 Year Member
Agree, but those numbers are not in Holley terms. The 86/93 jet sizing is for Proform carbs. They use a different numbering system for their jets than Holley. You can't directly cross over the sizes between the two manufacturers... a Holley 70 jet is not the same size as a Proform 70 jet.
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