engine hunting, what should I be looking for???

[69gumby]

I am getting ready to head out to the wrecking yards to look for an engine to build. I am looking for a 350 with a 4 bolt main. I have a list of engine block casting numbers and thats about it. Are there any other things I should be looking for that would make one engine better than the other? Any casting humps, bumps or numbers?

[Senator350]

68 and earlier heads have no bolt holes in heads. you're probably going to want the bolt holes.

[kcjones]

You may hear this more than once, but I have to say it: You're a lot better off buying a block. Newer, sturdier, better metallurgy today, you know exactly what you're getting, and you dont' have to have it bored/honed/decked/checked/cleaned/painted. I want to build my own engine, too, but I'm certain going new block or better yet new shortblock 383 with forged innards is the kind of foundation on top of which you can make many horsepower for many years without hassle.

If you must junkyard scrounge, you won't find a lot of 4 bolt main 1/2 t trucks in the 70's - 80's. They were almost all 2 bolts. Look for 68-72 hi-perf cars with small blocks would be my guess. Or, 70-72ish hi option pickup.

[dfosh]

If you go for a used block don't worry about four bollt vs two bolt . The two bolt will be fine . However make sure it is in good condition . If you have never rebuilt an engine you might save money buying a crate engine .Check the cost of all the machine work that will have to be done to the one you want to rebuild .

[69halfton]

i thought that most trucks had 4 bolt main?

i thought they were built as low horsepower mules, and built to last. i.e the 4 bolt?

[Old Yeller 1970]

From what I'm told, trucks of the 69-72 vintage are the most likely to have 4 bolt mains besides the impossible to find muscle cars of that era. Mine is a 4 bolt, 10% tin, 20% nickel block with "010" and "020" cast on the front (under the timing cover) and rear (under the transmission bellhousing) of the block. That makes it one of the toughest factory blocks available.

My brother has a '75 1/2 ton 350 but it's only a 2 bolt. Maybe 3/4 and 1 ton trucks were more likely in later years to be 4 bolt but that is only a guess. IIRC, my brother's block was a high tin "010" so that makes it better in that regard.

Since 2-bolt blocks can be converted to 4-bolt, you might look for the high tin2-bolt block and and convert it over.

[prg machine]

You can build a very healthy engine with the standard 2 bolt mains. The 4 bolt thing is way hyped out for street engines.

[Wrenchbender Ret]

Generally if the upper hole in the block by the bell housing is drilled & tapped it is a 4 bolt main. Most all the 70's 80's 3/4 & 1 tons are 4 bolt mains but have small valve heads. Like the guys are saying, you dont need 4 bolt mains for a street engine.

[kookykrispy]

Unless you are planning a high-rpm 400+hp engine, 2 bolt mains will be just fine.

[MonteSS454]

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

This will tell you what casting numbers to look for.

[kcjones]

If you're going to build a high-rpm (over 5500) over 400HP engine, you'll want forged rotating assembly and the 4 bolt. But I agree with the other buys, 2 bolt and cast should give you a long life of cruising and you can still safely make good power.

[PanelDeland]

If you really want 4 bolt mains,you can have them added at the machine shop.The outers will be splayed and are supposed to be in a stronger part of the block webbing.

[Chevymann1968]

IIRC the splayed 4 bolts are stronger than a factory 4 bolt main!!

[Pont406]

It will be hard to find a good one a pick a part. Most of 67-72 trucks are striped of drivetrain very fast. If engine was in it, it was opened up. Scavengers get there before everyone else. By the weekend all the good stuff is gone. I go there sometimes for small stuff. Craigslist maybe a better deal. Goodluck.

[Longhorn Man]

i can't believe no one has said this yet.
you don't want an old 350. Get a 5.7 engine.
The one piece rear main seal is a nice feature, the center bolt valve covers are great if you get the leter heads with it, but most of all, the 5.7 engines have a revised oil system, and a roller cam.
I'm sure you've heard how the normal oils you get off any shelf is low zink, and will end up wearing out your camshaft lobes (and all the talk is VERY acurate) The roller cams don't need the Zink.
A high nickle 10/20 block is great, a 4 bolt is cool, but in all reality, it's all useless if the cam gets wiped every 50,000 miles or less.

[phipp13]

not all 3970010 blocks are 4 bolt mains i have both 2 and 4 bolt 010 motors. the stamp on the right front block just fwd of the head should have a 2 or 3 letter suffix example V0605TJC OR KO50TJZ THE TJC AND THE TJZ is the suffix and both are 4 bolt main motors there are many others also Happy Hunting. imho I'd be looking for a late 90s 1 pc rear main seal, fastburn heads, roller motor. reasonably priced and can make good hp on the cheap

[LuckyHenriksen]

You should look for a Gen III =]

[chevy29267truck]

ok if you want v8s the best years for the engines are 1968 and 1969 you want 4bolt main engines 327 302,DZ 350 400 396
now if you want inline six engines years 1967,1968,1969,1970,1971
1972 the chevy 292 or if the chevy 250

[dieselarmy13]

I'm with everybody else here on the 2 bolt mains being over-rated, but I'm also on Andy's side with finding a newer engine. SOME things do get better with age.

[prg machine]

Originally Posted by chevy29267truck

ok if you want v8s the best years for the engines are 1968 and 1969 you want 4bolt main engines 327 302,DZ 350 400 396
now if you want inline six engines years 1967,1968,1969,1970,1971
1972 the chevy 292 or if the chevy 250

there weren't 4 bolt 4 bolt 4 bolt 4 bolt 327s

[prg machine]

here's watcha do.................call the local Chevy engine machine shop Guru guy..................tell him to use one of his blocks he already has checked out (cost me 150.00, I didn't have to pull it, hot tank it or mag it...........it was all done) tell him whatcha wanta do and call it good. That guy who does it everyday every week every month every year is the guy to talk to. forget the yards, the shopper papers, the bulletin boards etc.

CALL THE MAN!!!!

[LuckyHenriksen]

Good idea

[69gumby]

Thanks for all the information! Now I'll have to look into that 5.7 engine idea. My truck has AC and I wanted to stay with the original compressor. Will all of my other parts bolt on to the 5.7, alt. and power steering pump? I did find a 3970010 block except the stamp code threw me when it came out as a 165 hp engine. Must be the heads that make this one such low hp.

Oh by the way, HAVE A VERY MERRY CHRISTMAS AND THE BEST NEW YEAR!!!!

[Gray Ghost]

Man you hear some funny stuff on this board. Some of what I have read here is the exact opposite of what most engine builders will tell you....you'll have to be the final judge of course, but here's an old guys' take on it.

From what I gather you want to look for a 010, 014 or 379 block. The newer blocks [80 to Gen ll intro] are nowhere nearly as well cast as the older ones. The high nickel content is what you want if you want a tough motor that will stand the test of time.

Forget about the centerbolts...especially ANY from the 80's cars or trucks. GM wasn't building good motors then. It was a time when the stop gap motors and trannys were built when the EPA was running rampant putting restrictions on emissions and mandating MPG figures. From '89 on they weren't too bad, but before that I wouldn't touch one or the transmission behind it.

You are going to have trouble finding a good motor at a yard although it's not impossible, craigslist would be a better idea. There is a ton of truth behind the 2 vs 4 bolt motor and most of the 010's [the most desirable block of the old ones] were 2 bolts. Some say the 2 bolts are stronger and I've had both and I can't dispute that a bit.

As to the oil/zinc thing...I've been running vintage blocks all my life and have never had a minutes trouble with a cam, nor have I hear a word about it from any car or truck expert. Not saying it ain't true, just that it's never been an issue for anyone I've ever known. I've always run Castrol oil...not sure what the zinc content is, but again, no trouble.

All that said, Lucky has a point....the gen lll's are the best motors to come out of GM since the 350's were put to rest and the 5.7's took over. For me, there's nothing good in between and I wouldn't waste my time.

Finally you can add a roller cam & timing chain to any small block. I had one in my '78 Elky SS and that motor is still running today with over 200k on it. I will say the one piece rear seal is a very cool thing...but that's about the only good thing about an early 5.7 IMNSHO.

[Longhorn Man]

facts;
The vortec heads outflow any stock iron small block head
the 5.7 is just as good as the vintage blocks... not many vintage engines made it 200,000 to 500,000 miles and never been rebuilt
Early 80's engines were just as crumy as most 70's engines, it was the crap on top the engine that made them lame
Zink has been removed from oils for about 2 years now, look into it and it's effect on old school cams.


Talk to the people who you plan on working with on your engine build, talk to the cam people, get pro advice on top of ours.
Might want to look over on the engine and drivetrain board too.... this has been covered there too.