Project 6-71 340 Demon

I have an all forged bottom end. Stock crank, many have said (including a couple of blower companies), it's up for the job, Eagle H-beam rods and heavy TRW forged pistons. I also talked to a few builders that told me they have never had a single keyway balancer problem at the boost levels I will be running. The rotating assembly is balanced and I will be using Cleavit 77 H series bearings. Steve Morris Racing is providing the cam.

Jack

Jack, will you be using full groove main bearings and what intake manifold?

We all know to run extra piston ring gap with boost.
I havent seen a Mopar crank fail using a single keyway. But a cast crank with a single keyway might be asking for a problem.
SB chevies cranks crack quite often in a Roots 71 blown application. Not the keyway, the whole crank snout cracks. It takes alot of HP to turn that blower. Also, the closer you keep your pulleys to the damper the better off you are. The further out the pulleys are, the more leverage exists to add side load stress.
I wouldnt waste money on the girdle. The weak point is the head gaskets in a sb Mopar.