512 4 bolt short block : racing components value ?

[George W.]

Hello all . I am looking at a 512 4 bolt long block assembly dated L280 , no stamp pad info (milled ?) , 074 heads (don't have date codes yet) , guy wants pretty good $'s as he says it it is a Corvette LS6 engine . ???? The deal is complete with following all CORRECT for a '71 LS6----- exhaust manifolds , oil pan , intake , carb , dist. , balancer , water pump , brackets , shielding , valve covers , etc. , etc.. It was used as a drag engine and has studs in the block (in lieu of head bolts) , is 30 over , has one sleeve , and comes with a 671 blower , Hillborn injection , another set of closed chamber rec. port heads (291's) , big holley dominator carb , aluminum water pump , aluminum pulleys ,and dominator rec. port 1x4 intake . My question is , what can I expect to "recover" by selling the drag racing parts --- injection , blower , 291 heads , aluminum stuff , intake and carb ? Thanks in advance for any ideas here , Geo

[Joe L.]

Re: 512 4 bolt short block : racing components val

George-----

I can't tell you what the racing components might be worth as I don't "dabble" in that sort of thing. However, I can tell you this: a 4 bolt, '512' block used for an LS-6 is absolutely NO DIFFERENT than a 4 bolt, '512' block used for any other application. Especially since this one has no pad stampings, there is no way to verify it ever actually was used for a Corvette application, not that that matters very much.

The lack of numbers on the stamp pad may mean the block was surfaced ("decked") OR it may mean that this was a crate engine, especially one built up from a GM-supplied bare block or short block. If decking is the cause for the lack of numbers, then there should be "circular" broach marks on the pad.

[George W.]

Re: 512 4 bolt short block : racing components val

Thanks Joe . I have a line on a "real" '71 LS6 vert. missing the engine , hense my interest in this set up . As stated above , seller wants pretty good $'s for this , so I would like to "recoop" some of my cost if these two deals go through . Geo

[Joe L.]

Re: 512 4 bolt short block : racing components val

George----

I wouldn't pay any huge premium for this engine unless you can confirm that you can recover a lot of it from the extra parts (which, I doubt you will). '512' blocks are not rare.

[Mike M.]

Re: 512 4 bolt short block : racing components val

george: examine the pad under magnification. if you've looked at a # of original broachmarks(running perpendicular to the long sides of the pad) and it appears to have tonowanda horizontal broach marks, then you have a much more valuable(1-2K) case than a rotary broached marked case as you'd see with the local machine shop removing the pad #'s to deck the block. mike

[Warren F.]

Re: 512 4 bolt short block : racing components val

George, Joe : I believe that this block has been used both as a 427 & 454 cid configuration. Be sure that this block has the notches in the cylinder bore to accept the 454 crank, that would be the difference in the application for that casting no.

[Joe L.]

Re: 512 4 bolt short block : racing components val

Warren-----

The '512' block was originally used for both 427 and 454 cid applications. However, regardless of application, the block will have the reliefs for the 454 counterweights. The reliefs were an inherent part of the '512' casting. Basically, this was a block designed for 454's but used for some later 1969 427 applications.