I have just located about 15 12-bolt chevelle rear ends they have the coil spring perches on them along with the trailing arm mounts. Do these need to be shortened? I think the Regal rears are 52.5" from backing plate-backing plate.
The 1968-72 A-body 12-bolt will work in the G-body in unmodified form, but the SSM 1328 kit (or the current Lakewood equivalent) is needed. This kit includes the upper control arms, spring mounts and shock mounts necessary to adapt the A-body rear to the G-body chassis. Welding is obviously required, though not an problem for you. The wider A-body rear may require some additional measuring when choosing wheels - the extra width may affect the backspacing options. Good luck, Rick
Awsome news. Cutting rear ends is not my thing but the mounts are no problem. Cheapest I found is from a 72 chevelle 12-bolt, coil spring perches, not sure about the trailing arm mounts for 125. 3 miles from my house.
Look at the ports of a manifold opposed to a shorty header. Most of the ports on a manifold aren't even square. I'm going to use manifolds in the interim, but I'm going to matchport them before I install them. It sucks when you run out of $$$...... :ball:
Thats why I have set a limit. I will spend no more than 2k on parts. I am trying to stick to this budget and am doing very well thus far. The killer is going to be the rear end getting new gears and carb. It kinda sucks seeing all these parts that I would like to use but the word budget is becoming a very loose term lately. :laugh: I have gutted the engine bay of all non-essential wiring which is actually most of it, pulled about a mile of wiring out of just the engine bay. The only thing I kept is the wiring for the starter and solonoid, front lights and signals, water temp sensor, and some constant hot wires never know when your going to need these. I pulled the AC and put it in the proper filing drawer aka "da dumpster" Since this is a street/strip car heat and AC won't be needed. Im trying to get as much stuff out of the engine bay as possible to make it more "clean" looking as if was suppose to be there. I cleaned off all of the grease and crap that collected on the engine cradle over the last 18 years. And will be powerwashing later today then airing down the car and prepping the bay for paint aka "spraybomb". I have the TA motormounts in hand and am a little dissapointed in these $104 for 2 hunks of metal. I could have fabbed these up at work in 2 minutes, along with the motor mounts. I might make a copy of them out of carbon steel, just in case. Too bad at work they keep a close eye on titanium.
71-72 BOP "A" Body rear FWIW, the 71-72 BOP "A" body rears come with a "retainer" plate instead of using "C"-clip eliminators. Used one for a year or better in a 3510lb 80 Lemans that went 1.40 60' and never did break. Not suggesting that this is a good idea; but I wouldn't be the least bit afraid to run one in a mid 11 sec ride or something that just goes high 1.50's or slower. Rob a limited slip carrier out of a 70-81 Trans Am and it'll bolt right in the 71-72 BOP "A" body housing. Have seen these limited slip units on E-bay for under a $100.00 or there in that neighborhood (price-wise).
Thanks for the info I did end up getting the 12 bolt a-body rear. Very nice condition and the gears look like they are in good condition. I haven't counted the teeth yet so Im not too sure on the gearing. This will be getting a set of new 4.11 w/posi when everything is said and done. I'd like to get everything done on wenesday then put the new spring (OEM) and shocks (CE) so i can get a nice level base to start with the motor transplant. Looks like this won't be a winter project after all. But the winter will give me enough time to start increasing the HP of the motor since stock is no fun.
12 bolt found If you take the service cover off and turn the ring gear; you can spray the the outer edge of the gear with carb cleaner and you'll see the factory part # (asuuming they're original GM gears). Beside that # will be a two digit #, like 42 and then right beside it will be a smaller # like 11. That will be your number of teeth to divide by if you don't won't to reach through housing to count your pinion teeth. BTW; if they turn out to be 3:31's and you don't want them, I would be interested in them. 4.11's sound awfully low; do you just mainly run 1/8 mile? Be nice if you get it going before winter and run the car in the cool air.
I did some calculations and the 4.11's will be way too tall, re-thinking on 3.73's. I'll check next time I get a chance and let you know. Finally got a carb form a guy at work for free. It's a 750DP but not sure if thats too small for the engine, its a 70 Stage 1 motor with an Edelbrock mani.
On my mild Stage 1 combo an 850 was worth nearly 2.5 tenths over a 750 . This was a 9.5:1 motor with heads that were in the 240ish cfm area.
Sorry I haven't been around in a while but the project is coming along very slowly because of all of the winter vacations I've been on. But the motor came back from the builder and is very strong. The front suspension is on and the car is rolling, finally (only took 6 months). While I was away the TA motor pads came, although the old 307 mounts are still on the car Im assuming these will need to come off and the new mounts bolted to the engine with the pads bolted to the bottom of the mount, then the motor dropped in with the tranny (lined up of course using the crossmember), then lowered and leveled in the engine bay. Then mark the position of the pads, pull the motor back out and bolt down the pads and lower motor mounts and then drop in the motor. Can someone check me to see if I have everything down? This seems like the easiest way to get the job done.
