engine and tranny question?

hey Im kind of new to the american car scene and need some help. I am getting a 86 monte carlo ss with no motor or tranny for $1000. I was thinking of putting in a 383 stroker with 450hp. I need to know what tranny should I get for the car? It will not really be a daily driver I will just cruise around every now and then and race it on the track. I want to keep it an automatic to. Any help will be great.
thanks Justin

At 450HP you've just about excluded a stock 200-4R, and are right on the edge of capacity with the later design 700-R4 and 4L60 (not "E" variant) transmissions. Any of those can be built to withstand abuse at a 450HP level and probably 400 ft/lb of a decently-tuned 383, but a stock unit with stock internals would have to be a late ('88 or later) 700-R4 or 4L60.

You're way beyond what any T-5 and most T-56s would handle without serious rework, too.

The engine will put out over 400 lbs of torque. I was thinking about getting a th350 or th400 performance tranny. Will the engine and tranny go in pretty easy Im putting them in my self?

thanks justin

If you don't care about overdrive and gas mileage, the TH400 is nearly bulletproof.

thanks.
do you think I will need different motor and tranny mounts with the th350 or th400 and the 383 stroker? Will I also have to customize a header back exhaust?
thanks
justin

A Monte SS would have had a SBC engine, so the mounts would be the same and exhaust dimensions would be the same. You may have to move or modify the transmission crossmember depending on the trans you install (different bell flange to rear mount dimensions) and probably will have to get a custom length driveshaft with either the TH350 or TH400 (different overall length to tailshaft).