Not sure what you mean here. Do you mean single stack 1911 frames? They're all the same size -- the caliber will affect the slide and barrel rather than the frame. I have no experience with their hi-cap kit, so I can't say much there. Forty caliber 1911's can be a big headache, as the rounds are too short for the magazine.
I think I understand the question. The frames are basically the same, but the feedramps are different. The feedramp angle for 38 super is different than for 45 ACP.
If you want to build a .40 you will probably want to go with a ramped barrel. The ramped barrel will help with feeding since the .40 is shorter than .45, and it will also help support the case more.
I was recently told that just buying a frame with a standard .45 feedramp and then cutting it for a ramped barrel may not be optimal, so make sure you check with a qualified expert before making your purchase.
Call Caspian and ask for Gary Smith. Tell him what you want to do, and he will tell you what frame to start with. They offer both the Para ramped barrel cut and the Wilson ramped barrel cut.
<font size=-1>[ This Message was edited by: GrandmasterB on 2001-06-04 10:39 ]</font>