Automatic transmission ideas

[mrr1999]

Hey guys. I'm in the process of putting my drive train together on my 69 Camaro and I was trying to figure out which way to go. Since converting to a T56 isn't in the cards this year, I was looking at the 700R4, 2004R or 4l60E.

Which is the most logical to go with regarding cost and conversion man-hours?

I am running a 454 that will put out about 425 hp to the crank, and the car currently has a TH400.

Thanks.