I am too lazy to take my oil pan off and look right now but if any one could tell me if both the l-48 and l-82 are four bolt main blocks? I cant read the numbers and the engine color is not factory and the valve covers are aftermarket so I dont know if it is a 48 or 82. This fact isnt too important, if they both are 4 bolt mains. I am deciding if I should use the block in the car or use another one to build my 383 stroker. Thanks Guys!

I forgot to mention the car is a 1979.

1979 L-48s are two bolt mains. L-82s are four bolt mains.

Bill

L48 has the 2-bolt mains and the L82 has the 4-bolt mains. My L48 has a plaque on the console that states 8.5:1 compression and 270ft/lbs torque. The L82 would list 9:1 comp.

Thanks guys for the responses. Is their a way of telling which my car has quickly? Will the vin tell or the option codes in the door jam?

Locate the engine VIN number on the front passenger side of the block. If the engine VIN ends in: ZAC, ZAA, ZAB, or ZAD it is a L48 195 HP. If the engine VIN ends in: ZBA or ZBB it is a L82 225 HP. This is listed in my repair manual under engine identification for 1979 Corvettes.
I have seen plenty of two bolt main small blocks make 400 HP and live. Just depends on how many rpms you want to turn and how harsh you drive/race it. You may want to use ARP main studs instead of bolts for added strength if you use a 2 bolt main block.

You could also get aftermarket splayed 4-bolt caps added. Some say that is more desirable than factory 4-bolts.

the free restoration package from GM has much of the above information in it. it's a good source of info. if you don't have one, there is a thread posted fairly recently with a phone number of where to call. I just don't remember it. maybe some other member can give it to you.
Hank

Check the rear of the block where the bellhousing bolts up.There is a number cast in the block if the last four numbers are 0010 that should be a 4-bolt main block.

Dave from Easton,PA

I have two 010 blocks in my garage. One is a two bolt the other is a four bolt. The made them both ways. If it has an 1/8" pipe plug on the front of the block between the timing cover and the intake, it is a four bolt block.Otherwise it is a two bolt.