rrt898

I am in the process of changing my cam, heads and intake. Today I dropped the pan and saw that I have a 4 bolt main. I got one number off the passenger side on the rear of the block 14088548. That number tells me 86-88 block. I was just wondering if some L-98's had a 4 bolt main?

WVZR-1

I believe that to actually ID the engine you need to work with the information on the right pad only. All else would be just speculation. What is that information? I don't know that in '86 that there would have been a VIN "derivative" vertically behind the oil filter housing. Maybe .. FSM says (optional). OA-3 in FSM for image and locations.

Post the right side information and IF the VIN derivative was there on the rear then there's the PROOF

JrRifleCoach

Why produce a 4 bolt block for a TPI engine that only runs 5500rpm?
If its original its an oddity.

Joe C

can't swear to it, but i'm pretty sure my 85 is a two bolt main. the OP's casting number (14088548) is correct for all 86 corvette L98 blocks ONLY (the casting number was actually used throughout the GM 350 line from 86-88). according to this site -

http://www.mortec.com/castnum.htm

14088548 could be either 2 or 4 bolt main. no advantage I can see by having a 4-bolt in a basic stock L98.

as WVZR-1 says, other alpha-numeric info would verify it's pedigree -

Churchkey

Dip stick on the left side or right side?

Right side dipstick is a one piece rear main seal block 86 & up. If 4 bolt it may have started life in a truck or it is an over the counter block. Check if flat tappet or roller cam block before cam selection. Roller cam snouts are different, top timing gear is different, they use a cam thrust plate + a "spider" for lifter alignment.

If left side dip stick it is a 85 & earlier gen 1 block. If so be careful about cam selection you need a cam for a gen 1 block. If a roller you need a gen 1 cam & link lock lifters.

THE 383 admiral

it could be the truck block with both Roller & Flat provisions. this 86 - 88 block number shows 2 OR 4 bolt.
http://www.enginelabs.com/news/refer...sting-numbers/

WVZR-1

OP asked if some did - The only way for the OP to determine the ODDITY of the build is to supply the information from the "pad in front of RH cylinder head" and/or confirm the VIN derivative vertically behind the oil filter mounting pad.

All else the OP can confirm from his "tear down" - he's by now likely done with the tear down and's maybe only interested in the "ODDITY.

There are certainly the differences that are noted but the OP specified a "casting number" so we're left to assume it correct.



If it could be validated that this was a "service engine" or an "over the counter" then it's quite likely sufficient to justify the 4 - bolt build. Without information ones just left to "wonder".

There's validated build of 3.54's I believe in '92 cars - on paper it's a "shouldn't have been possible".

rrt898

The dipstick is on the right (passenger) side. The block is not a roller motor. I will get more info when I take the heads off.

thanks

Jonnie Law

that isn't entirely true my dipstick is on passenger side and it's a roller motor I have upgraded with cam and heads

vader86

Its from a truck or the Camaro, original engine probably blew. 86 Corvette had 2-bolt mains from the factory.

Hot Rod Roy

The dipstick on my '84 is on the right (pass.) side, and that's what's shown in my FSM.

AR420

HD applications?? 3/4 and 1ton truck. They did that later with the Vortec L31. Cars had 2 bolt and HD trucks had 4 bolt mains

coupeguy2001

86 was a transitional year for chevrolet.
my 86 came with 2 piece seal 2 bolt block with flat tappet cam, rh dip stick.
in addition, i had a piston noise, and tore it down to look.
I could find nothing. So i took it to a machine shop, and he mic’d the pistons and the bore.
he said one piston is not right.
so i bought a piston from chevrolet.
machine shop supplied the rings and honed the block.
the rings only fit the new piston.
i guess there was a “light” ring pack for 86.
rings were thinner.
took the piston back to chevy, and there was another number.
took 3 weeks to get the piston, and it matched the other ones.
then machine shop scoured all the books, had mc quay norris on the phone, they made up a set.
the service rep delivered the rings to the machine shop, and because it was so mich trouble, i let them assemble the short block.
So, long story short,
rh dipstick,
flat tappet
one piece seal
different pistons.
i believe my car had the first edition alum heads too, since it was an early 86. When i took the iron heads off, put the aluminum 113 heads on it, the front tires stopped hitting the outside edges of the hood on bumps.
the first edition alum heads were prone to cracking, and there was a recall.
GM put iron heads on in place of the alum.

jazfe

I must have a replacement motor because my late 86 is a 4 bolt block.
I'll have to pull the numbers now and check.

DMITTZ

Back when I had a SBC in my 88' C4 I pulled the engine and found it was 2 bolt main engine. However another fellow in my club pulled his L98 and found it to be a 4 bolt main block. I'm guessing the majority were 2 bolt main blocks, but once in a while due to production supply issues a few 4 bolt main 'truck' blocks may have occasionally found thier way into some C4's.