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hello could any one tell me anything about this engine please . i know its been rebuilt with a bigger cam but dont know what spec also has roller rocker and new pistons .also know its 4 bolt as i have had an inspection camera in the sump the last pic is of the top of a piston pic taken through the spark plug hole
Last edited by trans am kev; Jul 6, 2020 at 05:22 PM.
3970010 GM SBC, got one in my car. But your was made in Mexico, mine in USA. back in 75.
What's inside - who knows?
Somebody engraved a plate that means something - who knows? Oops, my mistake you say that's ingraved on the piston top?
get the casting number from heads; in there around springs. They look like OE chevy heads of some sort; they still have the OE steel umbrellas & exhaust valve rotators (yuck).
block has the two-piece rear main seal; all OE roller cam blocks have one-piece rms.
heads are not Vortec; they're a much earlier, conventional version; their casting # will tell the tale.
heads appear to have No guideplates & roller rockers appear to Not have self-align/rail feature.
Having neither while running rollers is often an unsatisfactory choice/oversight; typically rollers won't run true on valve tips.
Take a pic between the rockers on the head......look for numbers or markings.
STD bore is unusual.....this may have been an over the counter block.....made in Mexico means after at least after 1980......post a pic of the front block pad too.
My money's on it being a vanilla 350.
But possible it's a 377; "383" or old 400 crank (w/ mains turned down) with 400 rods & std 350 pistons.
Much speculation; suggest pull pan off & cam out so, going forward, you'll Know.
Instead, if you install wrong damper / flywheel, you'll also "learn."
To properly identify the engine, you need to post a picture of the numbers on the stamp pad on the block in front of the passenger side head. There should be suffix and prefix letters as part of the number that identify what the engine was originally installed in and its configuration. It will also tell where the engine was built. The casting number was used on a lot of different configurations. IE: hp, 2 bolt or 4 bolt mains, etc.
even then, since they are replacement pistons we gots no idea what the cam is, deck height- but most likely stock .020-ish. what the heads are. so we can tell no more than OP can by googling his pistons. https://www.summitracing.com/parts/slp-h631cp as somebody mentioned, possible a new bare block from Chebby. which is a better explanation for non-stock pistons than they rebuilt the engine with new pistons and didn't bore it out. and note: these pistons can only be used with a longer stroke by using the short 400 SBC rod. which nobody does. they don't even use them in 400's. so this IS a 350.
Radley chevrolet in VA sells these new complete engines. Used to be 1600 free ship. Now about 2200. Many other dealers, Pace Performance, Summitt, Jegs, lotsa places.
I have the same block. It was in my car when I bought it. Target master 350-250. I trashed everything but the block. Builder talked me into using it. He said those Mexico blocks were good with high nickel content. Now it's a 383-450 with RhS heads, roller cam, and rocks and rolls ( Hencho in Mexco??))
There is no such thing as a "high nickle" block....from GM. A myth created around 2011-2012 by some internet board wanted to make a faction of people think they had something special...and possibly make an average block worth more to the uninformed. All GM blocks have some nickle content but it was not designed into the block...it was for production efficiency at the foundry. The first cast "high nickle" block was the original World Merlin BBC around 1996 or so.......
I just want to clear that up because false information in this hobby makes me cringe.
Jebby
Last edited by Jebbysan; Aug 27, 2020 at 09:04 AM.
identify my engine please
