VCCA Home Forums TECHNICAL - 1945 AND NEWER 1971-1979 4 bolt mains

I have a mid 80s 350 from pickup-can I tell from casting #s if it has 4 bolt main and where do I look for #s-trying not to pull pan if I don't have to-member 046505

think you're gonna have to pull the pan.mike

Lexey,
It is not always conclusive but I have found that a 350 block with a 1/8 pipe plug in the front of the block, high above the water pump will usually have 4 bolt main caps. I don't know why, and I am aware that it sounds stupid.
Someone put me onto this several years ago.

Mike

The suffix code should tell you volumes ... its the letters and numbers (the letters are the code!) on the head surface of the block, right side ...... problem is they sometimes get milled off when decked.

Most 350 pickups and station wagons were four-bolt but not all.

Whats your suffix code letters?

If its from a mid 80's pickup I'd bet that its a 2 bolt. When the blocks changed to a right hand dipstick all but the heavy duty engines had 2 bolt mains. As mentioned, the suffix on the right front head surface will indentify it's original home.

Thank you all-I'll see if I can find #s today-If I remember correctly it had quadrajet and 40000 miles but low compression(sat for long time)and new radiator which may indicate that it got hot-if it is 4bolt and internal specs check out is it worth anything as I'm trying to finance full resto of 1930 4dr sedan and running out of funds rapidly as I'm sure we all do with these projects-thanks again and I'll be in touch shortly

Hey Lexey, private sellers with 4-bolt engine cores think they have something special and put big prices on them. A low cost source is a Chevy or GMC dealer. When they replace an engine they either have to turn in the core or pay a $100 core charge.

My local Chevy dealer had several 350 CID cores and let me pull the pans off them to find one still on the standard bore and with a crankshaft that was in perfect condition. All he asked was that I reassemble them, meaning putting the rod and main caps and pan back on.

That worked out for me and for $100 I got a complete 1978 4-bolt engine core minus accessories, flywheel and harmonic balancer.

Ray