I've got the chance to get a complete '91 460 EFI with 67k on it for $500. I'm considering swapping the 351m out and dropping this in, mostly for towing power, I know that the 351m shares the bellhousing bolt pattern with the 70's 460's, but are the EFI 460's the same? What about motor mounts?

would the C6 trans hold up, or will i need to find an E4OD and swap that in as well. It's currently mated to a ZF5 and a transfer case, but this will be going into a 2wd auto.

 

Your 351 probably makes more horsepower and torque than a 90's 460. I see the point of swapping in an early 460 but not a later one.

 

A 77 351m put out 161hp/262lb. 91 460 numbers are 230hp/390lb. Almost 50% increase on hp and 33% on torque.

 

I stand corrected. I figured the ol 351 to put out more than that.