I have a block, 3970010, date e205 with a smooth right front pad. Is this because all replacement engines are blank? It also has the plug in the front above the cam. I read all 4 bolt engines have these. Iam guessing its a 1975.
May 20, 1975. The odds are good it's a 4 bolt main, but not 100%. For most applications, it does not matter. The block was almost certainly decked, you can tell by the surface finish--they were broached at the factory, you won't see that finish from any resurfacing machine that you'll find in machine shop. A belt sander will come closest.
The front pad is smooth as a babys butt. Decking would change the intake and pushrod geometry, right? How does the intake fit if the block is milled?
I wouldn't think they'd deck it so much that it would interfere with head/ intake fitment, but I guess you never know. Probably just enough to zero deck height the pistons.
In 1975 and generally true for the 010 blocks from the 70s...4 bolt main blocks were used in L82 Corvette...3/4 ton and heavier trucks and probably 4x4 applications. I'd say the odds of it being a 4 bolt block are approximately 5%-10% since the vast majority of Impalas..Novas..Camaro..vans..just about everything else using an 010 block in 1975 was a 2 bolt main..
yeah, but....I'd say 90% of the mid-late 70s 350s that are still around were installed in trucks, and almost all of them were 4 bolt mains. So the odds of it being a 4 bolt are still really high. And from what I've seen, the generic 2 bolt 350s used in cars in the early 70s were mostly all 014 blocks. I recall seeing one 2 bolt 010, and a whole bunch of 4 bolts.
Are these the L82 pistons or L42 pistons. To me they are flattop with valve reliefs, some may say they are dished.
The number of main cap retention bolts is a finishing process, meaning that it can be applied to any block. All 010 means is a casting designed to be finished with 4-in bores.
Nope. I have worked on tons of 2-bolt main blocks with that plug. The only reliable way to determine how many bolts hold down the main caps is to pull the oil pan off the engine and count for yourself.
I have seen a whole mess of blocks that let go on the bottom end. On quite a few of them the split was in the web, and went right through an, or several, outboard cap hole bores.
so they would have been better off with 2 bolt blocks.... I guess my buddies don't go that fast. The only problem I've seen with a 4 bolt was in a work truck, never been apart, one of the outboard bolts was laying in the pan. Didn't hurt anything.
It is certainly a matter for debate. I would like to get access to one that had such a failure for analysis. It would need to be determined if the damage would have happened either way, and just happened to cross that bolt hole, or the web was weakened by drilling a hole in it. The few that I have seen had split out right down the bolts. This is OEM Iron stuff we're talking about, not aftermarket race stuff, placed under extreme stress. I put a stud girdle over the caps on my block, because I did not want to run this test live.
I skipped right over small blocks when I was young, started with big blocks, that have really beefy main webs. I guess I missed out on all the fun.
It would mess with intake fitment for sure, you then have to machine the mating surfaces on the intake to fit properly, or deck the china walls to compensate. You would need shorter pushrods, but it shouldnt mess with the geometry in terms of the angles due to engine being a 90 degree design.
What if it was decked less then .010, would the intake and pushrods still need work? My intake does not look like it was reworked.
it's probably fine. Those blocks were never square from the factory, any time you want to build one well, you need to machine the deck surfaces, but usually not enough to screw up the intake fit.
I put a scope thru the front timing chain area and it looks like a 4 bolt main engine. Let me know what you guys think. I could not get a good pic going into the oil plug.
Intake, or the end-seal areas of the block would need a tuneup. I prefer to do it all on the block. Nothing need be done with the pushrods. The angle change is nearly negated by readjusting the rocker arms. What little is left is negligible.
Jim, That is an excellent pic in post #4 you posted . I wonder how many numbers matching blocks in extremely expensive cars have those same inline marks on the decks ? Just makes you wonder some time ,,,or at least it does me . Tommy
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