Before you tell me to search , I already did and it is still inconclusive about the GSR girdle on an Ls block. If you use the main caps of a GSR and bolt that on to an Ls block using GSR bolts will the the GSR girdle then be a bolt on besides the dowels and the bushings needing to be pressed? Or would the Z10 be a better idea, I know the bushings are still necessary even for the Z10.

 

Mix matching main caps is not a good idea. You want to use the mains that came with the block to get proper fitment for bearing and crank. Other wise if you switched around mains you would need to get it align honed and thicker bearings and hope that all fit right.

Just use the GSR girdle on your LS mains and get it machined to fit as well as the bushings pressed in. If you went with the Z10 you would still need to get it machined and doweled to fit properly. Do a search under block girdle, gsr girdle and z10 and you will get plenty of info regarding these procedures.

 

I've heard using a Type R girdle is a good substitue for the Z10. The Type R girdle can be machined to fit the LS bottom end.