73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Rapid Roy on November 14, 2016, 07:50:29 pm
-
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
-
how much are you looking to spend? are you looking to give it some kick just for fun or for towing/hauling?
-
Do not have an idea of cost, of course, don't want to spend more than needed. Want the extra kick for fun. Not planning on doing very much towing/hauling. Truck is primarily a daily driver/cruiser.
-
do you need a new motor or do you want to work on the one you have now?
-
Not sure if I need a new motor or overhaul. Found left head gasket leaking coolant on rear. Plus have pan, front main, rear main or all leaking. Not sure jut yet what all is leaking. In process of diagnosing leaks. This is why I do not know which route is best, or cheapest.
-
If your farming out this job, it could be pretty costly. Economically, and quicker way to get in your truck and go.......a crate motor would be the way to go, IMO. approx. 1500. + you get the guarantee.
-
about 2k for the crate and a cam change should get you about 400 hp/tq. rich has the setup
-
Anyone thinking of getting a crate engine better act fast because i think papa Trump is going put big tariffs on ANYTHING made in Mexico.
Not trying to get political here, this is just my gut feeling and observation. Thank you.
-
Anyone thinking of getting a crate engine better act fast because i think papa Trump is going put big tariffs on ANYTHING made in Mexico.
Not trying to get political here, this is just my gut feeling and observation. Thank you.
Unfortunately it Needs to be done
To keep every last job we have from going to Mexico or China
But it needs to be done gradually
But it will also have to be done thru congress and the only time they work fast is when they are voting themselves another raise or taking bribes , uh I mean campaign donations from lobbyists
Sent from my iPhone using Tapatalk
-
What carb did the truck come with?
-
Carter (Rochester) 4BBL. Quadrajet.
-
Why do you want to rebuild the original engine?
-
Found out definitely have front and rear main seal leak. Left head gasket leak at rear. Was not sure which route to take. I could have all leaks repaired. Heads redone and will not have any leaks. I was told by technicians over 20 years ago, that if you had the heads redone, that it more than likely would start burning oil cause it would cause more compression to piston and cause the old piston oil seals to leak and burn oil. I am not sure that this will happen, but I can imagine that it could. Then I would need an overhaul to repair. So, with a new crate engine, I would not have to deal with that.
-
Ok, so the stock 350 (ls9/lm1) with 4 barrel for 74 was making about 160hp@3800 and 250tq@2400rpm.
If you are going to go crate, then i actually recommend this 305:
http://www.jegs.com/p/Chevrolet-Performance/GM-Goodwrench-1996-2002-Truck-305ci-230HP-50L-Engine/2814064/10002/-1
The basic 350 crate is not bad, but this one has roller lifters, higher compression etc.
i think this will give you a little more power while maybe getting a little better mpg.
-
I would recommend this GM 350 engine instead of the 305 recommended earlier by Stewart. Its got 4 bolt mains, Vortec heads and a mild roller cam.
http://www.jegs.com/i/Chevrolet-Performance/809/12530283/10002/-1.
You could get close to 300 hp out of this engine by just adding long tube headers with duals, and a good dual plane intake and carb. If you swapped in an RV cam you should be able to get at least another 20-30 hp and still have a very smooth drive on the street.
Bruce
-
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.
-
Refurbishing the heads will have zero impact on oil consumption past the piston rings. Quite the contrary, with properly sized valve guides and new valve stem oil seals, less oil will draw past the guides into the combustion chambers. To boot, new intake gaskets may better control oil drawing into the intake runners from the valley area. Conceivably, oil consumption might decrease.
For best results I recommend Viton positive-stop valve stem seals (no machining required) used in conjunction with the OEM square-cut valve stem o-rings caged between the valve stem locks (keepers) and spring retainers for both the intake and exhaust valves in lieu of the OEM umbrella seals.
-
I agree with Bruce.
The L31-R should still have provision for the pre 2000 transmissions. The 305 Stewart recommended does not.
There's no replacement for displacement. The L31-R 350 comes with Vortec heads. The L31-R is 255hp 330ft-lb compared to 230hp and 285ft-lb on that 305 with the stock Cast Iron exhaust manifolds and intakes used in the 1990's T400 chassis. You can eke a few more horses out with better exhaust and intake manifolds.
The L31-R cam doesn't have a fuel pump lobe and the block is not machined for one either so you will be installing an electric fuel pump to use the Vortec 350.
You can use the GMPP #14097395 Camshaft from the HT383 & 350 RamJet without otherwise changing the L31-R valvetrain for some more HP & a lot more torque. Roughly 280hp & 400ft-lb... This will void the engine warranty tho.
Your Cast Iron Quadrajet intake will not fit the Vortec heads. If you want decent driveability and fuel economy without sacrificing much, if any, performance get an Edelbrock Performer Dual Plane Intake and install a properly rebuilt 4M4E Quadrajet.
You will not be sorry you moved up to that 350 and the upgrade is inexpensive. Keep your factory engine in the barn or garage.
-
I agree with Bruce.
The L31-R should still have provision for the pre 2000 transmissions. The 305 Stewart recommended does not.
There's no replacement for displacement. The L31-R 350 comes with Vortec heads. The L31-R is 255hp 330ft-lb compared to 230hp and 285ft-lb on that 305 with the stock Cast Iron exhaust manifolds and intakes used in the 1990's T400 chassis. You can eke a few more horses out with better exhaust and intake manifolds.
The L31-R cam doesn't have a fuel pump lobe and the block is not machined for one either so you will be installing an electric fuel pump to use the Vortec 350.
You can use the GMPP #14097395 Camshaft from the HT383 & 350 RamJet without otherwise changing the L31-R valvetrain for some more HP & a lot more torque. Roughly 280hp & 400ft-lb... This will void the engine warranty tho.
Your Cast Iron Quadrajet intake will not fit the Vortec heads. If you want decent driveability and fuel economy without sacrificing much, if any, performance get an Edelbrock Performer Dual Plane Intake and install a properly rebuilt 4M4E Quadrajet.
You will not be sorry you moved up to that 350 and the upgrade is inexpensive. Keep your factory engine in the barn or garage.
Really? i thought ALL 305's will accept any of the common transmissions----th-350,400, 700 etc.?
The reason why i suggested this 305 over the more popular 350's is that Roy wanted more umph than his present engine, which i think this 305 can provide AND the mpg will not be any worse and probably a little better. i understand and agree that for the most part 350's are superior to 305's in power, but in this case you get decent power without being too much engine, better fuel economy, less wastefulness.
-
I agree with Bruce.
The L31-R should still have provision for the pre 2000 transmissions. The 305 Stewart recommended does not.
There's no replacement for displacement. The L31-R 350 comes with Vortec heads. The L31-R is 255hp 330ft-lb compared to 230hp and 285ft-lb on that 305 with the stock Cast Iron exhaust manifolds and intakes used in the 1990's T400 chassis. You can eke a few more horses out with better exhaust and intake manifolds.
The L31-R cam doesn't have a fuel pump lobe and the block is not machined for one either so you will be installing an electric fuel pump to use the Vortec 350.
You can use the GMPP #14097395 Camshaft from the HT383 & 350 RamJet without otherwise changing the L31-R valvetrain for some more HP & a lot more torque. Roughly 280hp & 400ft-lb... This will void the engine warranty tho.
Your Cast Iron Quadrajet intake will not fit the Vortec heads. If you want decent driveability and fuel economy without sacrificing much, if any, performance get an Edelbrock Performer Dual Plane Intake and install a properly rebuilt 4M4E Quadrajet.
You will not be sorry you moved up to that 350 and the upgrade is inexpensive. Keep your factory engine in the barn or garage.
Really? i thought ALL 305's will accept any of the common transmissions----th-350,400, 700 etc.?
The reason why i suggested this 305 over the more popular 350's is that Roy wanted more umph than his present engine, which i think this 305 can provide AND the mpg will not be any worse and probably a little better. i understand and agree that for the most part 350's are superior to 305's in power, but in this case you get decent power without being too much engine, better fuel economy, less wastefulness.
Read the link you posted on that engine... apparently the LSx and later 4.3L v6 were not the only engines that require the newer Gen III style transmissions. Something was changed about the depth of the crank flange in relation to the bellhousing face IIRC.
Yes and no. .. The 350 doesn't have to get significantly less MPG than the 305. I've had a stock 1985 305 and a properly setup truck 350 get right around the same 14-15mpg highway fuel mileage and 11-12mpg in town. The 350 had more torque on tap when I needed it but was not working real hard to make the pickup roll down the highway. Certainly nowhere near peak torque where you use a lot of fuel.
It is a package deal... The choice of carburetor, intake, exhaust, and cam along with tires, axle ratios, and transmission setups have a serious effect on fuel mileage. A Carter AFB or Rochester 2G will not sip fuel like a Quadrajet on the primaries or a good TBI or MPFI system. Using intake, cam, exhaust, and heads to increase lower RPM torque will improve MPG. Set your tires and gearing up to take advantage of the torque/HP curve is essential too.
The L31-R is a cheap way to get very good heads and reasonable cam on a fresh motor for comparatively not much cash leaving you free to optimize the other parts of the package...
-
i dunno; i think that engine should be able to accept pre 2000 transes----the L30 is the same as the L31 just 305 vs.350. i think the link says IF you're putting it in a 2001 or newer truck, you gotta use the 2000 and after starter and trans.
Anyways, whatever; i was just suggesting this engine because it does (at least on paper) offer more spunk than the stock LM1 350 AND the L30 305 has roller lifters and higher compression too, so it should get better mpg than the original engine.
-
I'd rather (and have on 6 occasions) rebuild my own engine to my own specs than to invest in a crate motor hecho en Mejico no matter the savings on the crate motor.......cheap parts and cheap labor equal cheap engine.....you just need a competent machinist to prepare your block and heads.......chevy small block parts are readily available for reasonable prices in a varierty of combinations to make some serious HP for less than $2500 including machine work....putting a reliable performing small block together is not rocket science........ IMHO