The guy that will probably be installing the 455 in my car says that I can use my 350 turbo trannie with the 455. IS this true? And if I can, then what will i be losing by not using the 400 turbo?
Yes it's true. What do you give up? Transmission longevity, and reliability. The THM350 can be built to take the abuse, but it will cost some more. A built 455 +traction + heavy car= bye bye THM350. You can do it, but don't beat on it too much especially with sticky tires. It won't last too long. You can always use it until you find a 400.
That's my plan, use the 350 Turbo until it's toast. That was three years ago and I'm still waiting. Course I'm only running 13s with 1.95 sixty foots, it really depends on your plans, how much power your making, how fast you want to go. Hey I heard one time that some years of 350 had an extra clutch in them, anyone have any info on this?? Dave Berry
If you're going to spend some $$$ on a new tranny, consider an overdirve unit like a 200R4. It will cost about $2500 when it's all said and done, but you'd have a well built trans and be able to cruise down the highway and still get off the line quick because of it's better gear ratios. It's the best of both worlds. I'm doing a conversion in my car now from a built-to-the-hilt th400.
