I have already bought a Radix (112 I believe) and an LQ4. I was lied to and was told it was an '02, but it turns out it is an '99-'00 iron header! Since the crank is longer I can't bolt up my T56. I'm having a hard time selling this motor, so I'm forced to make this one work.
What's the best budget stroker combo that will support a Radix 112? I don't want the 112 to be a restriction, though, so nothing too outrageous. Since I'll have to change heads too, is there a combo that works best with the Radix and strokers?

 

The MP112 won't support anything well larger than a 6.0. I'd suggest swaping out the crank for a 01+ 6.0 crank or a 5.7/5.3 (same stroke). Those iron heads flow well and are the same port config as the alum 317's from what I remember....just iron.

 

What cranks will fit without modifications? I know the Gen3 cranks will fit, but which is ideal? Are LS1 cranks the same stroke? Wouldn't the rods/pistons need to be balanced with a different crank? I thought these motors were internally balanced...

 

5.3,5.7,6.0 cranks are all interchangable. Same stroke, same rods. Theoretically a 5.3/5.7 crank in a 6.0 would need a re-balance due to the different weight pistons but truthfully the factory balances are not very accurate compared to your local speed shop.

 

Would a 5.3 rotating assembly be interchangeable? If I got a 5.3 crank, I'd need to get it balanced with the 6.0 rods/pistons. What if I were to get a 5.3 rotating assembly and use that instead of the 6.0 internals? Or would the 5.3 rotating assembly be weaker than the 6.0?

 

5.3,5.7,6.0 rods, and crank are all the same strength.