Transmission for racing

[Gunstar1]

I'm trying to decide which transmission to use in my 77 Firebird for drag racing.

What I currently have:

77 Firebird with a 305 2BBL and a TH350 transmission.

What I want to do:

The 305 is going to come out and be replaced by a Pontiac 400, 428, or 455.

I don't plan to go nuts with the engine, but I'd like to shoot for a low 13 second to high 12 second car. But I also want the car to be streetable.

What I'm thinking about is:

Getting a BOP TH350, but I don't think this will handle the torque of the big PMD engine.

Getting a BOP TH375, but I don't know much about this transmission. What is the good and the bad of this transmission? Is it a beefed up TH350, or is it a downgraded TH400?

Getting a BOP TH400. I know this will handle the torque, but it's bad for sucking down horsepower, passing a lower % through to the wheels.

Getting a TH200R4 (used in the Buick GN/GNX). I think this will hold up fairly well due to the fact that they are used on the GN and with a rebuild, may handle the torque of the big PMD. I may be wrong on this, though. The extra gear for cruising would help the mileage.

I'd like to avoid a lot of fabricating to use one of these transmissions.

Any suggestions?

[FormulaLT1]

I think you should send Hypsi who's posted his GN in Member's ride a PM and ask him about the TH200R4. As for the Rest of them I haven't used any of the GM Auto tranny's Except for the 700R4 or 4L60-E . So I really wouldn't be any help to you.
John