C4in mesa

I dropped my L98 off to the machine shop Wed. 12-26-12. Fri the shop owner called me and said he found where the leak was coming from. I posted several threads about leaks that never seemed to end. He said there is a 4 inch long crack in my block. I asked if he has a core and he said maybe ? I Googled whether or not the L98 is a 2 bolt or 4 bolt. Weird but some guys claim that their motor is a 4 bolt main stock ? Maybe a factory screw up I have no idea ? Anyway my friend has a 4 bolt main he will sell me if the shop owner doesn't have one. My question is can I use it as a core ? What specifically do I have to look out for when finding a core block ? I was under the impression a Chevy 350 block 2 or 4 bolt were otherwise the same. My build is only going to give me a 300-330HP motor so I don't have to have a 4 bolt but it would be nice for a possible future upgrade !

NuckinFutz93

The only thing you need to look for is a one piece rear main seal. 86 up blocks had them, 85 back did not. I would also look for an 88 up block for the factory roller cam. You can use the 350 block for an 88-95 chevy/GMC truck. They are 1 piece rear main, accept roller cams, and cheap. I've seen tons on CL for 75-200.00 dollars for complete engines.

GREGGPENN

OEM blocks for our Corvettes were "only" 2-bolts. You have to get a truck block to find/convert to a 4-bolt. That's what I did. 1-pc RMS is correct.

Block numbers were even the same! IIRC, the casting simple says "638" on the side of the block. There's a website/two around that shows the block numbers. (638 are the last 3 digits of 14093638)

Websites differ on the actual production dates...but I'd say the 88-95 range (listed above) would be correct (if 90's trucks never had the LT motor...or if they're interchangeable...I can't remember.)

OTOH, a casting number never changes and I'm 99% sure about the number I used and posted above.

NuckinFutz93

The 87-95 truck 350 was known as the L05. It came in 2 and 4bolt mains. They all came will roller cam provisions for the dogbones( lifter holder) and the spider( holds dogbones in place). You can use LT1 parts, but the L05 use conventional cooling. The heads on the L05 are not the best, IMO, I would sell them and run the stock L98s. I wouldn't run the L05 pistons either, they are about the same most of the late 70's smog dished pistons. They are a great block, without the Corvette engine mark up.

GREGGPENN

Good to know! Thanks.

You're referring to the designation I presume (like L98)? I was told my "638" 4-bolt came out of a Chevy Truck.

I assume L05 appears no where on the block? Recently, I've seen people asking for block numbers.

L05 (nor L98) isn't listed here either...
http://www.gearheadgeek.com/ghgj/ind...lock-casting-s

FWIW, I used AFR195's on mine.

NuckinFutz93

No, L05 doesn't appear on the block, but 5.7L does on the rear right( if you are facing the front) top the bellhousing flange.

It's still a cheap alternative to paying corvette prem price.

vetteoz

The casting # is just that , a casting #.
Has no bearing on what config ( designation ) the engine left the factory as.

The fabled "010" block was used for everything from 165 Hp truck engines to 370 Hp LT1 Vette engines
but every hot rodder swears his block came from a '70 LT1 Vette to the point where there are
more "Vette" 010 blocks running around today than ever left the factory clothed in fiberglass

slickfx3

splay suppose to be stronger

vetteoz

Or the '880 block from the later L31 Vortec 350 engine used in '96 - '00 trucks , vans and SUV's.
50% chance of getting 4 bolt