Cast Iron Crank Rev Limit

[Ashlander]

I recently swapped a Mach 1 motor into my GT, and went with the auto so I could use my GT's flywheel (engine is mated to a TR-3650). At the same time, I also installed the intake cams from the 96-98 Cobras to bump up the HP on the top end. The idiot that I am, didn't take the lower rev limit from the auto Mach into account when I decided on that. The engine doesn't start to really sing until around 4k. I know the rev limit for the autos was 5800. I'm wondering if that is due strictly to the cast iron crank, or to the auto transmission? How high can I safely rev the cast iron crank? I currently have my tune set to limit at 6000, just keep on the safe side for now.

Thanks for any input.

 

[DSG2003Mach1]

it wasnt strictly for the crank, that trans doesnt like to be reved, theres some clip or something like that in the trans that tends to back off and things go bad from there. They put the cast crank in because the rev limiter would be lower with the auto trans.

Im not sure on the rev or power limit of that crank though

 

[Roots-type]

That's for the auto, not the crank. Those cast cranks are good to about 600hp and are lighter than the forged pieces, so that's a plus unless you're getting stupid with the power.

 

[Ashlander]

So I should still be safe to take it up to like 6800-7000 like the 5-speed version?

 

[DSG2003Mach1]

So I should still be safe to take it up to like 6800-7000 like the 5-speed version?

Ive seen auto Mach guys do it, the only failures I ever recall seeing were the transmission

 

[Roots-type]

So I should still be safe to take it up to like 6800-7000 like the 5-speed version?

I don't see why not. I would.