Big block build and transmission options

[Jagged]

I'm building a big block for my '89. 454, .040 over, 427T heads, just under 9:1 compression, and crane's truck cam for idle-4600 (.485/.485 266/[email protected]").

Right now the truck has it's original 700R4. I can rebuild the 700R4 using the tightest tolerances, but I really don't think it will last. I'll be running 3/4 ton axles with 3.73's. With 31-33" tires my rpms at 65 MPH on another transmission (TH350/TH400/SM465/etc) with a 1:1 final drive is from 2628-2469 RPM. With overdrive, I'm only turning 1802 RPM.

So, we're looking at almost a 1,000 RPM difference between overdrive and a 1:1 final.

Basically, I want to drive 65-70 MPH without my 454 sounding like it's gonna explode. Thoughts, comments, suggestions?

 

[Chevy305]

go 465 and never look back!

 

[76zimmer]

I really don't know why people think 2800 rpm is excessive, most of these engines dont make max torque until close to 4000 or more. If your only running 26-2800 it would be perfect cruising range. Maybe not real great on gas, but if your running a BB that shouldn't be a concern anyway.

 

[Chevy305]

I really don't know why people think 2800 rpm is excessive, most of these engines dont make max torque until close to 4000 or more. If your only running 26-2800 it would be perfect cruising range. Maybe not real great on gas, but if your running a BB that shouldn't be a concern anyway.

X2...

My 305 will cruise around at 3250 rpm all day long.