1979 TA hi performance motor

[9999]

Originally Posted by Tracker1

P.S. The weak block Baron is referring to is the 500557 block used mid-1975 to 1977. Not a great block to build 400+ horses with. Avoid.

I have a 557 block that I was considering using and have done some extensive research. The conclusion was roughly this:
Do not take it past 6000rpm. Keep it below 450 hp if going to ~5500rpm. If sticking at a max of 4500-5000(low-grunt street engine; torque monster), there is a reasonable chance you could get 500+hp and it would live safely.
RPM is going to be the thing that causes the weaker 557 castings to slightly contort and that would then encourage the crankshaft to fail.
I would say for anything around 400hp, a 557 block would make a fantastic replacement motor so you can preserve the original block. Thankfully they are relatively common.


Have fun with the build!