Wanting suggestions about engine overhaul

[Bandit130]

74 C10 LWB 350/TH350. Has original 350. Want to overhaul and use original block, if possible, and also want to modify to give it more kick. What do you recommend? Bore over, cam, heads, headers? Would also like to stay with carburetor. I have not had an engine that has needed overhaul before.

TIA

[MikeB]

How long can the truck be out of service? An engine rebuild could easily take a month or more when you factor in proper block and cylinder head machining.

It could also end up costing more than this new GM crate engine.

http://www.jegs.com/i/GM+Performance...u4lhoC89_w_wcB

Make no mistake, this isn't a high performance engine, but with a small 4 bbl, headers, and proper ignition curve it's great for a pickup, especially one with 3.08 or higher (lower numerically) gears. And if you're so inclined you can install a slightly bigger cam for more mid range punch. I say "slightly" because its low compression does not lend itself well to cams that close the intake valve much later than the stock cam.

If you can afford more, here's a good choice, but it will need an intake manifold that will fit Vortec heads.

http://www.jegs.com/i/GM+Performance...g3_xoCRd7w_wcB

[Gregski]

Voodoo Hydraulic Flat Tappet Cam & Lifter Kit

$195

The most awesome 268 cam ever produced! Out-powers all others! This High Performance street cam likes 2400 RPM stall, 700 cfm carb, dual plane intake and headers. Makes un-equaled power to 6200 RPM with proper valve springs. If you're looking for a Very Strong cam with great street manners then this cam is it.

[Dead Parrot]

One option if you decide to overhaul your existing block, find some used vortec heads and have the shop rework them instead of your stock heads. As previously mentioned, you will also need a vortec intake. Before proceeding, get a firm price quote for the overhaul vs purchasing the equivalent new crate motor.

While doing the engine swap, might consider an overdrive transmission.

[Gregski]

What is your budget?

[Bandit130]

Working on a small budget.

[Gregski]

Originally Posted by Bandit130

Working on a small budget.

I hear you and not to be a jerk but give us a number: $500, $1,000, $1,500 etc.

I want to help cause I just went through this exact thing on a '74 as well, see my thread Restoring Rust if you have not seen it all ready it is long but super detailed down to part numbers, prices, specs, and procedures

Fact: engine rebuilds are expensive

[Bandit130]

could possibly handle 1500.00 to max. 2000.00

[Gregski]

Originally Posted by Bandit130

Want to overhaul and use original block, if possible, and also want to modify to give it more kick. What do you recommend?

OK, so $1,500 will be tight, but maybe doable

if you want more kick than start out by deleting all SMOG systems, Air Pump, etc.

ditch the stock cylinder heads, they are SMOG heads and the best way they were described to me since I also have a 1974 truck is that they were "The Best of the Worst Heads" LOL so ditch them not worth the $300 dollars to have them freshened up

Vortec cylinder head option, this is what I went with but they tend to crack so I had to buy 5 cylinder heads from a junkyard to end up with two "good ones" I think I paid like $100 bucks for both heads since I got them at a 50% OFF sale so you could get them and take them straight to a machine shop and drop the $300 on them for a basic valve job, wash, magnaflux, and new valve stem seals, nice little freshen up job. Remember Vortec heads will dictate you getting a Vortec style intake manifold so add $200 to that bill so you are already $600 out

A lot of guys overlook the gaskets, seals, and fluids. It all adds up. So add $350 for this part. That will be about $300 for a master gasket set (the machine shop may ask you to go out and get one on your own and deliver it to them) plus $50 for break in oil, etc.

we are up to $950

most machine shops stock .030 (thirty over pistons and rings) instead of .010 and or .020 just because of shelf space (got this from three local shops by interviewing them this year) so they will take your block to .030 over if not more, about $300 for wash, magnaflux, bore, and hone block. So now you need larger pistons, $100 for those, get them pressed on by the machine shop $50

we are up to $1,300

most likely you will want to replace your oil pump since you got the oil pan off, so $50, most likely you won't want to put your old water pump back on so $50, how's your distributor is it H.E.I. if not if it is points you will want to swap that to an HEI for $150

so we are up to $1,550

again just trying to be realistic and help you out

[SCOTI]

Originally Posted by Bandit130

74 C10 LWB 350/TH350. Has original 350. Want to overhaul and use original block, if possible, and also want to modify to give it more kick. What do you recommend? Bore over, cam, heads, headers? Would also like to stay with carburetor. I have not had an engine that has needed overhaul before.

TIA

OE block cleaned up as needed w/the OE heads cleaned up (or better flowing heads).
Select internals to compliment the heads (compression/cam specs).
Match a good dual plane intake & the carb to the heads/compression/cam.
Electronic ignition if it doesn't already have one.
Headers.
Trans converter (to match everything listed above as well as vehicle weight/gear ratio). For optimal results, you need to think of everything as a packaged system. Everything affects everything when spending money wisely.

One bit of info left out..... Is there something wrong w/the current short-block (knocking, excessive oil blow-by, smokes, etc....)?

[Bandit130]

Originally Posted by SCOTI

OE block cleaned up as needed w/the OE heads cleaned up (or better flowing heads).
Select internals to compliment the heads (compression/cam specs).
Match a good dual plane intake & the carb to the heads/compression/cam.
Electronic ignition if it doesn't already have one.
Headers.
Trans converter (to match everything listed above as well as vehicle weight/gear ratio). For optimal results, you need to think of everything as a packaged system. Everything affects everything when spending money wisely.

One bit of info left out..... Is there something wrong w/the current short-block (knocking, excessive oil blow-by, smokes, etc....)?

Found coolant leaking from rear left head gasket. Also leaking oil from other places. Pan, front main, rear main, or maybe all of them. In process of diagnosing where leaks are coming from. Smokes when starting and found out that the valve stem seals are bad. I do not like any fluid leaks at all. Did not realize this could be a confusing situation cause I am not an engine guy.

[SCOTI]

Originally Posted by Bandit130

Found coolant leaking from rear left head gasket. Also leaking oil from other places. Pan, front main, rear main, or maybe all of them. In process of diagnosing where leaks are coming from. Smokes when starting and found out that the valve stem seals are bad. I do not like any fluid leaks at all. Did not realize this could be a confusing situation cause I am not an engine guy.

Ok. Sounds like a bunch of miles so gaskets & valve seals failing. To have a better understanding, is there a specific reason you wanted to stick w/the original block?

A 74 vintage truck 350 is usually a good block casting but keeping it all 'numbers matching' doesn't really do much other than it sounds good. I opted to have my 7.4L rebuilt because the only cores they had on the shelf were 2-bolt main blocks w/cast cranks (mine was/is a 4-bolt main/steel crank). If they would have had a similar set-up on the shelf, I would have swapped w/o blinking an eye.

Some good suggestions were mentioned earlier for a budget friendly approach (GM crate motors w/Vortec heads). You'll get better suggestions/info more tailored to what you want w/more info.

On my suggestions, most don't concern themselves w/the entire package & wouldn't mess w/the trans converter. But in reality, the right converter & gearing (knowing what you have) can help make a better overall package vs the wrong converter/gearing (w/a fresh combo that's not tailored to your trans/gearing).

[SCOTI]

Originally Posted by Bandit130

Found coolant leaking from rear left head gasket. Also leaking oil from other places. Pan, front main, rear main, or maybe all of them. In process of diagnosing where leaks are coming from. Smokes when starting and found out that the valve stem seals are bad. I do not like any fluid leaks at all. Did not realize this could be a confusing situation cause I am not an engine guy.

This statement right here definitely tips the scales toward a crate combo.

[Tiger Joe]

don't waste your money rebuilding a stock 350. just buy a crate engine and be done with it.

stock 350 crates have gotten so cheap its making the engines practically throw-aways. plus no down time of the truck. you can order a 350 crate and plan it out and if you are good have the motor swapped in a day, weekend at most.

I had a 454 at the machine shop this spring/summer. I took good heads and block in just to be "freshed up" and I have over $1k in the machine work.

If your block needs bored out then you need new pistons. it all adds up quick and if you sit down and run the numbers that GM $1499 engine is a heck of a deal for stock replacement

[SCOTI]

Originally Posted by Tiger Joe

don't waste your money rebuilding a stock 350. just buy a crate engine and be done with it.

stock 350 crates have gotten so cheap its making the engines practically throw-aways. plus no down time of the truck. you can order a 350 crate and plan it out and if you are good have the motor swapped in a day, weekend at most.

I had a 454 at the machine shop this spring/summer. I took good heads and block in just to be "freshed up" and I have over $1k in the machine work.

If your block needs bored out then you need new pistons. it all adds up quick and if you sit down and run the numbers that GM $1499 engine is a heck of a deal for stock replacement

It also depends on what one is trying to achieve. For total stock rebuilds, a reputable 'mass' rebuilder usually comes in @ the same cost or cheaper vs crate. You mentioned your 454 so I'll add more info about mine for comparison. My 454 rebuild was $1250 out the door w/warranty via a local mass rebuilder that has a good rep w/the local dealerships. Mine was a mild rebuild (.030" over block; .010" crank) & I picked out my own cam & pistons from their source catalog (flat-tops vs dished, RV/towing cam vs OE grind). That was w/a Melling oil pump & IIRC THE cam/lifters were same source. This included new rockers, pushrods, balancer etc.... Turn around was 3-days after I dropped it off & I have 3k on the clock w/o issues from the engine/machining.

I do like crate engines in certain situations but like rebuilds just as well because you can upgrade some things w/o killing the warranty like w/a crate.

I'll say for the OP's situation, it depends on which crate motor is chosen vs options offered from a local rebuilder.

[Tiger Joe]

Originally Posted by SCOTI

It also depends on what one is trying to achieve. For total stock rebuilds, a reputable 'mass' rebuilder usually comes in @ the same cost or cheaper vs crate. You mentioned your 454 so I'll add more info about mine for comparison. My 454 rebuild was $1250 out the door w/warranty via a local mass rebuilder that has a good rep w/the local dealerships. Mine was a mild rebuild (.030" over block; .010" crank) & I picked out my own cam & pistons from their source catalog (flat-tops vs dished, RV/towing cam vs OE grind). That was w/a Melling oil pump & IIRC THE cam/lifters were same source. This included new rockers, pushrods, balancer etc.... Turn around was 3-days after I dropped it off & I have 3k on the clock w/o issues from the engine/machining.

I do like crate engines in certain situations but like rebuilds just as well because you can upgrade some things w/o killing the warranty like w/a crate.

I'll say for the OP's situation, it depends on which crate motor is chosen vs options offered from a local rebuilder.

Are you saying you got machine work, pistons,cam/lifters everything for only $1250?

That's pretty cheap if so!

I prolly have triple that in mine. But I went full roller drivetrain which added quite a bit

I agree with you different situations for everybody but like you said when I read his post and saw the last sentence that's why I recommend a crate.

[SCOTI]

Originally Posted by Tiger Joe

Are you saying you got machine work, pistons,cam/lifters everything for only $1250?

That's pretty cheap if so!

I prolly have triple that in mine. But I went full roller drivetrain which added quite a bit

I agree with you different situations for everybody but like you said when I read his post and saw the last sentence that's why I recommend a crate.

Yes sir. I kept mine simple enough to still work w/the factory TBI (w/a spec'd chip for the ECU). I did consider a hyd roller upgrade until I added it all up. Hyd flat tappet works fine for my dually/towing app.

I looked it up earlier.... The same place has 2-bolt/4-bolt 69-72 350 short blocks for ~ $530 w/a core. A guy could go through their catalog to see what cam & piston options they have (I used their parts source so there's no 'blame-game' related issues w/a different part manufacturer). I would imagine a guy could do similar w/a sbc build as well or @ least see if they'd go for a more aggressive cam grind from a source THEY recommend (again, Buy-In is paramount for warranty issues IMO).

Top that mild but decent sbc shortblock off w/some Summit alum heads (62cc chambers, 170cc int) for $1k ($1600 total) & you have a much better combo for the same $1499 as the 1st previously listed GM 195 (up to) 260hp crate. Would just need to pick a cam that works best for the heads.

I still stand by the crate suggestion in this instance though....

[Bandit130]

Thank you to all who have expressed their opinions on this thread.

Now I want to know if anyone has known that if the heads were redone and did not do complete rebuild, if the engine started burning oil due to older piston ring oil seals? I'm still unsure just what I really should do.

[Tiger Joe]

Installing heads that are redone on a bottom end that was not rebuild will not cause rings to go bad and burn oil

[tucsonjwt]

If it were me, I would go with a GM Goodwrench crate motor and just salvage what you can off the existing engine (brackets, accessories, etc.) There are lots of crate engine suppliers for reasonable prices. I have never had a rebuilt motor that I was satisfied with.

[rich weyand]

Get the 350/260 crate engine. Do NOT buy the 350/290 crate engine. BTDT.

[Mattchu60]

I would get the L31 crate engine over the 260 hp one - seems like it is setup better - vortec heads, 4 bolt mains, roller cam, 1 pc main seal. Probably another $4-500 over the 260 hp engine as well.

I rebuilt a 350 last year. 2-bolt block, 30 over, KB Pistons (9.1 compression), new iron eagle heads, R/V comp cam, edelbrock intake. Probably spent around $1600 for it all, assembled it myself. I hunted for deals on some parts that people bought but didnt use to try to save some money.

I'd go the crate route if you want simple. I wanted to build mine so I could learn more, but i know the combo I have isn't much more powerful than one of those GM Crates.

[rich weyand]

Originally Posted by Mattchu60

I would get the L31 crate engine over the 260 hp one - seems like it is setup better - vortec heads, 4 bolt mains, roller cam, 1 pc main seal. Probably another $4-500 over the 260 hp engine as well....

$2080 from JEGS right now, with free shipping. Which is a great deal for all that. If I had it to do over again, that would be the way to go.

The #10067353 350/260 engine is $1500 with free shipping, but if you have the extra dough, Vortec heads and roller cam is worth $580 extra.

[SCOTI]

Originally Posted by rich weyand

$2080 from JEGS right now, with free shipping. Which is a great deal for all that. If I had it to do over again, that would be the way to go.

The #10067353 350/260 engine is $1500 with free shipping, but if you have the extra dough, Vortec heads and roller cam is worth $580 extra.

Agree 100%.