tgilligan

Hi,
Looking to improve the initial take-off without replacing the gears to start. While a rear swap is in the future plans as there is either 2.56 or 2.73 stock gears in there now with an open carrier, wondering what else could be done in the interim. First plan is to change gear oil and freshen that up since I’m second owner and I have yet to do it so who knows when that was done last. I’ve heard that upgrading the torque converter could give me a little extra getup. A little background, I’m not drag racing or beating on this car. I rebuilt the engine and had machine work done, components added to increase power but from a stop light, she’s not very aggressive from a stop and I’d like to improve that just a little. Not looking to chirp the tires but some more oomph would be nice. I’m not expecting to feel any difference simply by changing oil and gasket but would a torque converter upgrade help? What stall would I be looking for as a small-moderate upgrade? Future plans is to work with Monzaz (Jim) to upgrade to a posi unit with better gears but that’s down the road. Thoughts?

matt69olds

If your happy with the engine performance, look for a good 200r4 trans. The lower 1st gear, combined with the overdrive, is the best of both worlds. Either rebuild the trans, or if it’s in good shape install a CK Performance shift kit, govenor, and servo package. The 200r4 trans will handle a mild engine easily with the right parts. While the trans is out, install a hardened stator support. The factory part isn’t heat treated and soft as butter. It’s common for the splines to strip off, leaving you with little get up and go.

matt69olds

Combine the trans with a gear swap (3.42-3.73 would be ideal) and you will swear the engine has a extra 100hp, and probably get better highway mileage than it does now.

Fun71

I drove a 70 Supreme 350-4bbl, TH350, 2.56 rear all through high school, college and beyond. In stock form with a good tune it was pretty good off the line. Over time I added a 2200 RPM stall, then camshaft, headers, lower rear gears. The stall made a difference on launching, even with the 2.56 gears.

70W-32

Are you sure that your timing and carb are maximized. Ive had several 4bbl 70 Supreme with 2.56 and 2.73 gears, and when properly tuned would easily spin the tire on launch

tgilligan

I’m confident both timing and the carb are dialed in. After the rebuild, I upgraded to an aluminum intake, Holley 750 and an MSD ready-to-run distributor setup. Changed the weights and springs in the MSD and set the timing based on the Comp cam. Idles and runs great. Never mashed on the pedal to even try to break the tires loose but I’m sure it would. My main question would be things to look for and check. I have a leak which I believe may be pump seal and if that’s correct I may upgrade converter when I drop it. Overall it shifts smooth so wasn’t leaning to replacing or having issues with trans. Maybe the fresh diff oil, new converter and a trans filter change it’ll make a difference.

olds 307 and 403

Yes, a 2000+ stall will make a big difference.