Paul, thank you! I have had some bad experiences with a few CAT products that customers supplied, mostly main cap girdles but have never seen the caps. At this point I wouldn't care about them being 1025 steel, as you said. What do you mean by "you will fully machine for the application"? Do they come with a flat bottom or do they have the step machined in for a 2 bolt block? I can machine the dowel holes and machine them flat if needed. Does the thrust bearing register need to be machined? The price is definitely cheap enough as long as they aren't junk. Do you know what angle the splayed holes are at? Thanks again.
Generally, they are identical in appearance (<---shape) to the Milodon ductile iron caps except that the CATs are made of steel and are black-oxided instead of gold iridited.
They are advertised as a 17-degree spayed cap. They are a single-register main cap made to be fitted to the D0VE-A blocks specifically, not a double-register cap (a la Blue Thunder) which is meant to have the standard-webbed (non-D0VE) blocks machined to accept the BT cap's outer registers. The thrust bearing register does not need to be machined because the overall thickess of all 3 CAT caps is equal to the OEM SCJ center cap's
thrust register thickness (this main cap width is adequate to accommodate all main bearings without any "overhang").
By "fullly machine," I mean that you will need to carefully prepare them as you would any other aftermarket main cap conversion, regardless of manufacturer: qualify the registers, measure and set the outter register cap-to-web gap, align bore, align hone, etc. My only recommendation specific to machining the CAT caps is to take slow, light cuts when align boring;
don't just plow through with big rough cuts to get to the final cut/hone (be sure to express this to the shop that does the align bore and align hone).
They come with new outer bolts (you are expected to re-used the OEM main bolts) and even a pilot for drilling the outer bolts (the pilot may not last for all 6 outer bolts, so think about getting extras from an engine tooling supply house). I see no reason why you couldn't drill the caps to accommodate the OEM block's dowel pins. If you want to replace the offshore bolts with ARP or something like that, that's up to you.
I understand your weariness about CAT products and won't dispute your general concern. Currently, my opinion on CAT is to watch out for those components that are made up of moving parts (rocker arms, waterpumps, harmonic balancers, etc), but not necessarily a single hunk of steel such as a main cap.
Remember that there once was also a time when most everyone bashed new-comers Eagle and SCAT because their parts were failing, but today they have their act together. I think that CAT is slowly working their way up the ladder, but personally I will use only their solid parts such as connecting rods and main caps and I will make sure they get a thorough dimensional inspection...but shouldn't
all parts get such an inspection in a high hp build? By the way, this is what I was originally alluding to when I said, "they are a single piece of billet steel which you will fully machine for the application anyway." Just be sure to check everything out.
Right now on Ebay, when I type "460 main caps" into the search engine, I find 4-bolt main cap conversions by Programm (<---U.S. made of 1045 steel), CAT, and ProComp. I prefer the CAT caps over the ProComp caps (the ProComp caps don't include the outer bolts nor do they include a drill pilot....and frankly I just don't care for ProComp parts....). Of the three brands noted above, the Programms are U.S. made, are made of the best material, and are the strongest parts.....but the CAT's are easily the strongest part of the cast iron block once they are installed (ie something else about the block will fail from execessive power before the steel main caps will).
Paul
