Jake_92RS

So I have a lead on a throttle body 350 out of an 80s truck thats a 4 bolt. Does this engine have the same block as a first gen SBC? Can it be run on a carburetor? Thanks guys, give me all the info you can on it.

Abubaca

iTrader: (3)

What are your goals? A 2 bolt main block will go a long way, BUT...if you've got a good deal on a 4 bolt, by all means proceed!

Yes and yes. .....pretty sure trucks went from first gen blocks all the way up the early 2000s, and then right to the 5.3 LSx. don't think they ever got the LT style engines like the Fbods, vettes, impala/caprice, before going LSx. ...regardless, that's not during the 80s. the only thing I would really watch for is whether or not it's a roller block. Depending on your goals it may not matter for ya. ...and once the later year vortecs rolled around, I think they lost the mechanical fuel pump provisions....but again, not in the 80's. What are your goals? Budget? Power? etc. etc. ...80s heads aren't so great. a vortec 350 is bout the best bang for the buck you can find.

sofakingdom

iTrader: (1)

Yup.

Of course. The block doesn't care how the fuel gets mixed into the air.

Not much "info" to give out.

It's pretty much an ordinary block. Nothing special, good or bad.

Don't get all worked up about "4-bolt"; not worth much at the level you seem to be at. As said, watch out for lack of mech FP provisions, and roller provisions as well; but other than that, it's just yerbasic 350 block. Nothing about it is any "better" "worse" stronger" "whatever" than about any othe r350 block.

cardo0

If u can remove the timing cover and look for some cast numbers like 010 or 020 it will tell u the block has extra nickle or zinc alloy. Also post the casting number from the rear of the block. Casting number is on drivers side and the date code is cast on the pass side. Also the stamped numbers on the from pass side has information like use/application code.

sofakingdom

iTrader: (1)

The 010/020 thing was only actually active for about 6 weeks back in about 1970; they found out REAL QUICK that it got too confusing to keep the mold plates separate, so they all got mixed up, and after that, whichever blocks all got cast with whatever end plates they grabbed out of the pile. The metallurgy went back to being specified as part of the casting number specs, as it should be and had been before and continues to be. So, ignore those numbers if you see any of them, they are meaningless.

A TBI block out of a truck is about 99.999% likely to be a 638. Doesn't matter though. Some blocks of that casting number are prepped for a mech fuel pump, some are not; some are prepped for the roller apparatus, some not (although they all got the cast-in parts of it such as the "spider" bolt bosses); and so on. Doesn't matter if it was a 89 ¾ ton Blazer, or a 88 1 ton pickup, or a 87 ½ ton Suburban, or what. Nothing about the application stamping is of any value. Don't even bother with that. All it will tell you, is what you already know; it came out of a 80s truck.

Most important things about it are its overall condition, and whether it has the mech fuel pump and/or roller provisions. All of which are NOT contained in any of the factory markings, and are best determined by examination of the parts themselves. Don't waste any time or effort on looking up numbers in such a situation as this.

Beeman

Also remember early SBC had a 2 piece rear main and a flange on the crank, mid 80's went one piece rear main and no flange. TB engines use a slightly different bolt angle on the inner intake bolts so a carb manifold has to be compatible or butchered to fit those heads.

sofakingdom

iTrader: (1)

Or, bought correctly to fit them...

DynoDave43

iTrader: (11)

If the OP doesn't mind my asking...sofakingdom, I'm only semi educated on SBC roller cams of this era (L03 / L05). When buying an engine like this, if I wanted to run a factory style roller cam/lifter setup, what do we have to watch for here? Sounds like the necessary provisions are there in all castings, but some not machined, while others are (even when not used)? Are these the mounting points for the spider that are machined/unmachined? Any other work need to convert a truck L05 to a factory style roller cam?

sofakingdom

iTrader: (1)

Right: the casting provisions are there, but the prep machining was not done.

Usually all you have to do is drill & tap the "spider" screw holes. They're ¼"-20 if memory serves.

The cam retainer screw holes are usually drilled & tapped but I can't guarantee that. There are 2 hole spacings; I've never seen any rhyme nor reason to which blocks got which spacing. 2 different retainer plates also obviously although only one with oval holes would do the trick for both. Too bad it doesn't exist.

I've heard from reliable sources, but never seen myself, that there are blocks that the top of the lifter bores aren't machined for the figure-8s to sit on them. That's a tough one. But, as cheeeeeeeeeeeep and plentiful as those blocks are, probably cheeeeeeeeeeper to just turf one you come across without, and go to yer local buzzard and get another core and pay more attention to it this time, than it would be to pay somebody to do that to a block lacking it.

DynoDave43

iTrader: (11)

Thank you sir.

cardo0

Hold on there quick draw. The 80's trucks had a lot of 305's and even 267" blocks. The chevy 400 was in production until 1980 and installed in a whole lota trucks also. W/o pulling a head and measuring the bore the casting number is the first place id look.

And most owners would like to know what the original application of the motor was regardless of present or future intentions. I think id like to know if it was originally a camaro block that ended up in a truck. But to eaches own.

BTW thats the first ive heard the nickle/tin numbers were bogus in the 70's. All i can say is hmmm. Thats . Not like i would have a block sampled either way. Or build it any different. The expensive aftermarket blocks boast "compacted graphite" now as stronger. Doesnt matter though ill never pay $2500 for a chevy block when i can buy core production block for $100 or less. Good enough for the speeds i race at.

Happy Holidays

sofakingdom

iTrader: (1)

Yes we all know that. We all also know that there weren't any TBI SBCs, 80s, trucks, or otherwise, other than the 305 & 350.

I'm giving the OP the benefit of the doubt, that he's actually looking at what he says he is.

And yes I know many block owners, especially inexperienced ones, think that the vehicle the block came in, makes it different somehow. Well it doesn't. Dinking around with that is an utter waste of time effort and energy that could be spent instead on something productive, like measuring it and perfecting it.

What you SHOULD HAVE said was "gee I always knew that wasn't the way a factory works and didn't make any sense, I'm glad somebody else finally came out and said it".

If you've ever worked in a factory you'd have a pretty good idea why; and if you know how a block is cast you'd know even better. The casting is actually done in sand, which is molded by a series of plates on the outside, cores on the inside, etc. that the sand is built up with. The end result is a hollow thing that looks like a "negative" of the part to be cast. (for example an ancient and very effective way of making a perfect sand mold involves wax: the thing to be cast is made of wax, then the wax plug is encased in sand, then a small hole is made and heat applied to let the wax melt and run out, then the metal can be poured into the mold) Then the molten iron is poured in, and when that step of the casting is complete the sand is busted up and goes back in the bin to be re-used. (the holes we call "freeze plugs" are actually there so that the sand that makes the mater jackets, can run back out when the block is done) According to people who worked in that particular casting factory, that was a short-run experiment whose original idea was to make blocks with the same casting number but some of them with inferior metallurgy, and keep them separate... turned out it was WAY too much hassle keeping those marked plates organized, and in fact the extra processing and handling cost more than the "savings" of the inferior metal; so they quickly went back to specifying the metallurgy as part of the casting number, as any industrial engineer would lean in school is supposed to be how it's done, but kept the plates with the numbers. (Industrial Engineering 101: 2 things with the same part # should be the same; 2 things that aren't the same should have different part #s) But once the "myth" entered hot-rodding lore it has become one of the most hallowed and worshipped nuggets enshrined in the mythology, and in spite of its outrageous contradictions with reality, no amount of truth or common sense has ever served to dislodge it.

cardo0

Dont know why u get all bent up over checking casting numbers. Cant see what hes got from 1500 mi away and a few min to look up the casting # takes care of that. And looking up the application could take less than a additional min. If u think thats a large waste of time then i think u should switch to decaff. Like it probably took longer for u to type up your disapproval than it would to verify those casting and stamp numbers.

On top of that the OP hasnt participated since his original post. Unless the OP shows some concern then i agree anymore advice here is a waste of time - but it would be mine not his time wasted.

So Tally Ho with your concentrated advice or whatever it is.

BTW did u actually work in a block casting factory or are u hoping everyone will believe what your imagination can virtualize? Ooops! There i go wasting time again when i should be rebuilding that block in the garage.

PurelyPMD

iTrader: (3)

subd