Friend is installing a twin turbo kit on his '90 Camaro. We're looking for a cheap but effective engine build.
I was think that it would be cool to find a factory 4 bolt block, since we don't have time or money to have his two bolt block converted to splayed caps.
So what applications should we look for at the We-Pull-It in order to get 4 bolt mains, 1 piece rear seal, and bosses for the roller lifter hold down tray?

I know all the blocks after '86 had the 1 piece seal and had the bosses for the roller lifter tray cast in place. However, what I've read tells me that in blocks built with flat tappet cams, the bosses are not machined.

So is there a way to tell, short of pulling off the intake AND the oil pan whether a block is 2/4 or setup for roller lifters?

From the research I've done, I've found the following casting numbers...

14088548
14093638
14316379 are all '86-'88 2 or 4 bolt 1 piece, roller or flat 350 blocks

14101148 There is some confusion about this block... http://vetteworks.tripod.com/casting.htm says that it is 2 or 4 bolt late model roller cam non-LT1 engines, while www.mortec.com says that it's 4 bolt only... If either of those are true, it's the block we're looking for...

Ideas? suggestions? thoughts?

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Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

I have the 14093638 block in my 88 GT - it is indeed a roller cam, 1 piece seal, 4 bolt main block. It came from a van and had been professionally rebuilt previously. A friend got the engine and when I found out what it was I talked him out of it.

I also have another roller cam, 1 piece seal, 4 bolt main block on the shelf at my brother's house (traded a 3 wheeler for it). I will check the casting # in the next couple of days.

As far as finding them easily... I don't know of any visible clues. The ones I have come across had already been inspected and confirmed but with unknown origins for what cam with them from the factory.

Hey Will my hotrod buddy always told me that 4 bolt blocks came in trucks .So check a truck that is post 86 and you might get lucky and find a one piece seal, roller block! This is what he always told me and he's been around a looooooooooooong time and he's crazy like us with his ZZ 430 powerd 75 Vega

NICE Vega!!!
Guy I knew in Pensacola had a 6-71/355 in a Vega...

I found a rebuilding site that listed the 2 bolt block for trucks and 4 bolt block for HD trucks... prolly 3/4 ton or better...

Was that van that had the 4 bolt block a 3/4 ton?

What do you plan on doing with that extra 4 bolt block?

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Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

Some of the HD half tons had the 4 bolts, AFAIK, ALL of the 3/4T and up had 4 bolt blocks. After '86, you're going to find the one piece seal. The roller cam issue I can't help you with as I don't typically work on SBC engines new enough to know what came with what.

John Stricker

It may have been in a 3/4 ton van, but I don't know for sure.

My spare block will probably wind up being a 302 with LT1 parts... Until then it will just sit on the shelf.

quote Originally posted by FIEROPHREK: Hey Will my hotrod buddy always told me that 4 bolt blocks came in trucks .So check a truck that is post 86 and you might get lucky and find a one piece seal, roller block! This is what he always told me and he's been around a looooooooooooong time and he's crazy like us with his ZZ 430 powerd 75 Vega

the problem is, some of the trucks still had a flat tappet cams instead of the rollers. I'm not positive if they all did, or some, or whatever it might be.

I dont know how to help too much. maybe find a 3/4 or 1 ton truck and pull the valve cover to get the a push rod. The push rods will be a different length for a roller cam, opposed to a flat tappet. Of course, there is still the issue of the 4 bolt main. Maybe the HD trucks all had 4 bolts, maybe not.

You might have better luck searching ebay for an old zz3/4 block. Also check the www.thirdgen.org You might pay more, but you wont be searching junkyards.

I did just win an 88 tune port 350 on ebay. I'll check if its a 4 bolt.

AFAIK, L98's, even Vette engines, were all 2 bolt.

Yeah, the flat tappet thing is frustrating. I guess GM just had to save the 2 minutes of machine time per block that it took to machine the roller cam bosses...

Doesn't help that the local We-Pull-It is seriously short on trucks.

I thought that GM went with roller blocks with all their engines? Oh well learn something new every day. Roller blocks are special in the fact that the have anti-rotation lifter hold down bosses cast into the lifter valley just above were the cam would be (centerline on engine) and not only a special machining proccess. If you pulled the intake you'd notice the spider that holds the anti-rotation tabs down. There are aftermarket hydralic roller retrofit lifters that work in originally flat tappet blocks. The SBC im building will use these as to it being an old two piece seal block. I think they are pricey though.

They cast the bosses into all the engines, but most of the sources I've heard say that the bosses were not machined in engines that were built with flat tappet cams. Aside from the lifter hold down tray, isn't there something different about how the cam thrust bearing works, or is that only in the timing cover?

So are the roller cam bosses machined in engines that were built with flat tappet cams? Everything I've heard so far says no...

I have a 1988 350 truck block. It was a flat tappet block, but has provisions for the lifter retainers and for the cam thrust plate. I do not know if the holes are threaded, but it appears the machine work was done and the holes are there.

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1986 SE 350 V8

I have seen more than a dozen post 86 engines without the bosses machined - all were running flat tappets originally.

The bosses not being drilled and tapped is not a huge issue, they are just simple holes and all they do is hold down the spider retainer, which keeps the lifter links seated which keeps the lifters from rotating. The lifter links are the critical part, not necessarily the spider itself. If it is off a few thousanths, as long as the links continue to remain seated it will work fine. I would just drill and tap the holes prior to sending it to the machine shop.

Never having seen a block without the bosses machined, I would have thought that it would be nice to mill the bosses to get the mounting plane for the spider correct. I would also have thought that machine shops would be familiar with this operation... but maybe my world in which fuel injection and roller cams are the way to go isn't the world most other Chevy enthusiasts inhabit, in which carbs are cool and flat tappet cams are great...

I realize that making the bosses work probably could be done with and angle grinder and a drill and a bottoming tap, but I'd rather get it done with a mill...

I just checked a 90ish 350 truck block that I bought a while back. It is a 2 bolt main, 1 piece seal that came with a flat tappet cam but the holes for the thrust plate and spider are machined and tapped.

Hmm....
Casting number?

quote Originally posted by Will: Aside from the lifter hold down tray, isn't there something different about how the cam thrust bearing works, or is that only in the timing cover? So are the roller cam bosses machined in engines that were built with flat tappet cams? Everything I've heard so far says no...

Duh forgot to add my post

Yes there is a plate that bolts to the front of the cam (before you install the cam gear). This prevents the cam from walking when it drives the distributor. Flat tappets don't have this because their lobes are machined with an angle that tries to force the cam towards the back of the block.The roller cams weren't designed with this angle because it would wear the roller on the lifter and create a twisting force that would make the rollerlifter try to rotate in its bore. If it rotated it would be bad news.

[This message has been edited by FIEROPHREK (edited 12-15-2004).]

Turns out to be an 86~88 block, casting number 14093638.