trying to find the year and size of my motor casting number 3970010 j0302tbf and 099f426333 stamped on font of block on small rectangle

 

http://www.mortec.com/castnum.htm Go wild. 3970010 is an incredibly common 350 block from the dark ages of the smogger mid-late 70s. There were other displacements built on the same block, but it's more than a little likely it's a 350. Not something I'd spend the money to rebuild even if I someone gave me the core for free. I had two of them at one point, rebuilt one and put it in a car, sold the car, then sold the other for $150 after having it listed on craigslist for a few months.

 

Is it worth building? i want to build it and drop it in my 79 malibu!

 

Not really... The heads, pistons, cam, are probably refuse. It's a 2pc rear main seal block, without roller cam provisions, with a driver's side dipstick tube that probably will interfere with stock Car manifolds. Kind of a big oil leak looking for a place to happen. By the time you rebuild or replace the heads, recondition the rods, bore .030" over, line bore, recondition the crank, and button it all back together you'll have 2 grand in it, meanwhile you can pick up a Vortec 350 GM crate motor for the same 2 grand with free shipping, a warranty, better pistons, better rods, better heads, a roller cam, 1pc rear main, 1pc oil pan gasket, centerbolt valve covers, etc.... And all without waiting for a machine shop to get around to your old greasy block, losing your parts, giving you the wrong gasket sets, or the wrong bearings, or the wrong rings... F the machine shop.

 

The.motor has alrady been bored .60 and runs like a.champ i was just going to put a flat tappet cam springs.lifters and new timing gears and chain and run it it will never see the strip just street

 

If its already running it's fine to swap in. Be careful with cam selection however. Cam choice should be made based on a ton of factors like axle ratio, compression ratio, cylinder head flow, etc. At the very least do some homework on the heads you have and see what the flow and what compression ratio you might have before you make a choice. it's very easy to go too large on cam choice, especially on a late 70s 350 with low compression and garbage heads, don't make that mistake.

 

If it runs, run it. Just don't dump a bunch of cheddar into a rebuild.

 

I was looking at a extreme energy cam would a set of vortech heads be alright? Would i have to shave them?

 

1. Do a search, Vortec heads have been covered a zillion times here and millions of other places on the internet.
2. I would not change the heads on this engine, if it runs, just dump it in and run it as Drew suggested
3. This is not the place for this discussion, this thread needs moved to the Tech/General Engine forum.

 

3970010 = 4" bore casting. Most common in 350's but also found in 302 and 327 engines since they all share the same castings.
TBF = 1970 350 Truck block. Nothing special.
099f426333 = Last part of VIN from vehicle it originally came out of.

It's not a fantastic engine by todays standards. A 4.8 or 5.3 LS engine can run circles around it. Still better than a 305 or V6 engine.

 

Thanks! Alkyiroc