[retired 56]

What transmission will I need with 350 ,385 hp and a 3.70 rear gear,I have A saginaw 4 speed everyone tell me it will not hold up, It is going in a 56 chev 2door ht Thanks

 

[Big Mouse]

Well, a lot depends on how badly you abuse the transmission. It may last years or hours - depending on how you drive it. I've talked to guys who have Saginaws that have held up behind some power, but they were not aggressive drivers.

I dumped my 4 speed in favor of a Tremec TKO 600 (rated at 600 ft*lbs of torque). I wanted overdrive & the freedom to launch harder and not be worried...

There are cheaper options, but I'll let others chime in as I didn't go that route...

 

[jimfulco]

If you don't beat on it too badly, it should do OK. Don't dump the clutch from a dead stop, etc. My Nova's had one for years, but I don't do burnouts, etc., and my clutch is the stock 10.4" unit. It does tend to grind a little bit on those hard 1-2 shifts, but it's done it for as long as I can remember, and it doesn't seem to be getting any worse.

 

[GCD1962]

I just took out a Saginaw 4-speed that has been in my '62 Corvette for over 20 years with no problem. The engine is modified and has 400+ HP. I don't abuse it, but do get on it once in a while. I didn't like the 2.84 lst gear (currently 3:55 rear, but I've had 3.70s and 4.11s in it at times). I bought one of the Auto Gear Muncie M21W which has a 2.54 lst.

 

[jimfulco]

Sags came with 4 different low-gear ratios. Go here to find out how to tell them apart: http://www.dandltransmission.com/saginaw.html