Are all 350 Chevys mostly the same?

[OldBlueDually]

I have started searching for a 350 to buy as a winter project for my truck. I want to build it up on my free time and then swap it in when I have the time. This way I'm not without a truck for however long it takes to rebuild the engine.

Anyway, I was originally searching for the same year 350, but I'm curious what changed about the 350 over the years. Were they all the same until the tbi 350? They all look pretty much the same to me but I know that probably isn't the case. Can someone educate me?

I will be parting ways with my 1976 GMC 350 (I bought the truck for parts). All original, all stock. Transmission included. It runs good too.

I even got my wife to yell at me.....it went like this: "what in the hell are you doing, your ripping up the grass"...yeah, a few figure 8's in the back yard I then explained I do the yard work anyhow, so it's all good.

Sorry for going off topic there. It does run.

 

[OldBlueDually]

@thecantaloupeman here is a pic of it, a bad pic at that (I took a snip from my video of it running).

You must be registered for see images attach

 

[Turbo4whl]

... the 350s did change here and there. Metal quality can change. There is the known "high nickel" blocks of the 73-74 era that some builders still enjoy to this day.

..... or the hipo small chamber 305 heads from the 80's make a damn good street setup.

So if I understand what both you gents are telling me, if this old man decides to build another engine.... The 350 in my 1974 Jimmy and the heads from my 1982 305 buried in the garage would make a good pair if married together?

What head casting numbers am I looking for? Thanks.

 

[Blackbeard44]

possibly, run the numbers, if I remember correctly the good heads had a 58cc combustion chamber? I am thinking that 1982 might be a year or 2 too old, the SS monte carlo i know had them, but there is probably more cars that came with them

if you just looking for a 300-350 HP motor it can be done fairly easily using the right combination of factory parts

 

[Ricko1966]

The 305 heads you are looking for are 601s or 416s. As for the 1970 370hp 350, you all know that was at the flywheel, and with no accessories,right? That method of horsepower rating went out 1971 or 72 so today's method puts it about 300hp. And too much cam and compression for a work truck. If I were looking for a 350 to build for a square I'd be looking for a roller block, 1 piece rear main, prevortec heads and drilled for a fuel pump. Dirt simple build, dirt simple swap, and no flat cam worries.If I had the thought that I might want to run fuel injection I'd look for a whole tbi suburban, there's an engine, wiring harness and all injection pieces.

 

[Rusty Nail]

The main benefit of adding smaller CC "305 heads" to a 350 is to increase the CR without having to change pistons...a guy can save big money. If your block is already gettin rebuilt in a machine shop...unless you are interested in trying to save other monies by using what you've got already.....dude a 601 head is 53CC and that is uber small. Gonna require super unleaded 100% of the time. Heads that small simply arent big enough to flow the air needed to feed your bored out 350.. There are too many better options yo and I think youd be leavin a lot on the table building a fresh block to run 601 heads..they really arent that great but dandy in a pinch IF YOU CANT CHANGE PISTONS. #416 way> #601.
I think youre lookin for trouble and it might be time to head back to the drawing board.

*Even a World Torquer or a Dart Iron Eagle would be a better choice than a #601..both cheap & entry level but offer vast improvements over stock.

 

[SquareRoot]

Nothing, absolutely nothing related to any 305 is good. Resist the temptation to drink the Kool aid.

 

[Ricko1966]

The main benefit of adding smaller CC "305 heads" to a 350 is to increase the CR without having to change pistons...a guy can save big money. If your block is already gettin rebuilt in a machine shop...unless you are interested in trying to save other monies by using what you've got already.....dude a 601 head is 53CC and that is uber small. Gonna require super unleaded 100% of the time. Heads that small simply arent big enough to flow the air needed to feed your bored out 350.. There are too many better options yo and I think youd be leavin a lot on the table building a fresh block to run 601 heads..they really arent that great but dandy in a pinch IF YOU CANT CHANGE PISTONS. #416 way> #601.
I think youre lookin for trouble and it might be time to head back to the drawing board.

*Even a World Torquer or a Dart Iron Eagle would be a better choice than a #601..both cheap & entry level but offer vast improvements over stock.

Not trying to stir the pot but on a smogger dished piston or rebuilder pistons parked low in the bore, the compression bump would be similiar to Vortecs on a flat top.And yes there are better heads cheap,but turbo4wheeler was asking about the 305 heads said he had a 74 350 and a 82 305 already and was asking about swapping heads I was letting him know which 305 heads were decent.Yep 53cc on flat tops would be a bunch.

 

[Ricko1966]

Nothing, absolutely nothing related to any 305 is good. Resist the temptation to drink the Kool aid.

There are a bunch of 350 heads that are not as good as 416s or 601s.

 

[SquareRoot]

Briggs and Stratton make better heads than any 305, and your still stuck with the worthless bore/stroke ratio.

 

[fast68chevy]

For the oddness mix. 1986 was the "special" year. Last year of the true carb atop the 350, but the first with a one piece rear main. It was also the last year to retain the angled manifold bolt down holes, where in 87, IIRC they went to the straight down with the introduction of the... sheer confusion I feel is TBI.

While I lucked out and had a set of large intake valve heads to use, it was still a relief that I didnt have a roller cam, wanted to learn the old school before even trying the new. Just if you do the flat tappet, if the lifter doesnt go in smooth, dont force it, and very much obey assembly instructions any cam shop directs for break in.

But to knock aside any of my rambling... the 350s did change here and there. Metal quality can change. There is the known "high nickel" blocks of the 73-74 era that some builders still enjoy to this day. Then like others said, the roller cams... thusly all the dfferent generations. I, II, III, IV, V... etc etc.

The heads sure as heck have a well documented legacy, eyeball the numbers closely, I have one set here that are the boat anchor "thin casting" version of the 882 heads. Plus you have the newer... much as i hate to say it, aluminum ones that are made. (I dislike the iron block/aluminum head idea, even if its sheds weight and can improve performance with a modern head design.) I personally chose to use Goodwrench Made in Mexico 882 clones of the 369 line, and they have done me good to the extent I drove from northern AZ clear to Buffalo NY and back, and not once did that engine show a single issue.

actually 86 was not the last yea for carb v8 motors. there were still many more factory carb sbc HEI large distrib style motors after 86... in alot of '87 and '88 F and B bodies both.. i have had a few... in 48 state emissions ones.. 8th VIN digit 'H'
ther were still many code 'H' base 305 Q jet HEI motors in these two model years. for example.

and also there were lots of 307 motors in 1987 to 1990, many different B body cars such as the caddy brougham were still the HEI old style distrib 4bbl Q jet motors. 8th VIN digit 'Y'

also many 1 ton trucks/vans with the code 'M' 350 old style HEI 350 Q jet motors as well.. M was 'heacvy duty' emissions,. with the extra heavy GVWR. amd these motors were cat converter/A.I.R. 48-state exempt, minimal emissions equipment on these motors.

 

[Snoots]

I can't believe a 305 is even in this conversation.

 

[Turbo4whl]

Nothing, absolutely nothing related to any 305 is good. Resist the temptation to drink the Kool aid.

The only reason I asked about the the 305 heads was because @Blackbeard44 stated they were a good choice. The '74 350 is still my choice for the '74 chassis it has lived in since 1974.

I see now there are more opinions against that choice.

PS: I have already had the Kool-Aid, but I had to give it up for Lent (and random drug testing).

 

[fast68chevy]

So if I understand what both you gents are telling me, if this old man decides to build another engine.... The 350 in my 1974 Jimmy and the heads from my 1982 305 buried in the garage would make a good pair if married together?

What head casting numbers am I looking for? Thanks.

66-01 an 4416 are toooow of the and theres a third oe but 4416 are the mooost common by far. on all the 1980to 86 F and B body 305 motors. L69 and LG4. mill them and larger valves and Z28 springs and enlarge tjhe intake runners and also smooth the exh runners and open up the bowls and they will flow good ok better and good for truck's heavy weight with good low end mid range grunt power with a RV cam and flat tops bored .030.. badass... ive made a few of these motors with modified 4416 heads and 3.73 axles and they are fun! or mill down and do all the same with a pair of 200 dollar good used iron eagles.

 

[Blackbeard44]

most heads that came stock on small block motors flat out suck, and in my opinion the small chamber 305 heads are the best bang for you buck, camel hump heads are nice and all if they have have accessory mount holes in them, 90's vortec heads arent bad, but the intake is a vortec only style