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Century ch3 Belt drive

Ok question is...

I have a Ch3 belt drive max 600 hp on my 400sbc. I bought a new modified LS3, and going to replace the 400 with the LS3. Looking at the flywheel it doesnt have the 6 bolt holes needed to mount up to the CH3 belt drive... What do I need to do? Buy a new Flywheel or a new Lower pully assembly for my belt drive or drill new holes in the new flywheel...
I suggest you give Century a call in the morning. Their web site talks about the LS on the CH4 drive but the CH3 page has no mention specifically about how to install to a LS platform.



There are flex plates commonly refereed to as SFI plates that for GM are like a universal fit with multiple bolt alignment adaptations. I would discuss with the Tech at Century and I have heard they are very helpful and easy to reach.
I once made this switch, required a new lower pully. We ran the dished jw wheel and it all bolted up no problem.

The new lower pully has a longer shaft 3/4" I think but don't quote me. The pilot hole on a ls crank is set back farther. You can run a spacer but i never have so not sure how good that works.
You can just change the shaft in the lower gear to the correct LS shaft. Heat it with a rose bud old shaft will drop out and put the new one in but you have to set it correctly for proper the stick out on the back side to make up to the flywheel/crank. We use a stainless band clamp with a dowel welded at the correct measurement clamp it on the back end of the shaft drop it in and let it cool back down.