L31 Vortec 350 vs Olds 350 for 1967 El Camino
October 1st, 2018, 05:56 PM
#1
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L31 Vortec 350 vs Olds 350 for 1967 El Camino
I am trying to decide which route to go. Either way, I want to keep this on a pretty strict budget and just have a nice car for cruising and road trips. Carb will be a 750 Holley vac secondary. Trans will be a th350 (it is a GM universal bellhousing model) and 1,800-2,000 stall.
Olds
I have a stock ‘73 short block. Number 5 heads. Roller tip rockers. I want to fill the heat risers. Also a valve job and flat tappet cam and spring kit.
Vortec 350
Basically stock with a cam and valve spring upgrade. .475” or so lift to avoid machining on the Vortec heads. I would buy an engine from a wrecking yard.
The pro that I see with the Olds is I won’t need to worry about an electric fuel pump and return line. But with the Chevy I will have the advantage of a roller cam and more efficient heads. I figure the electric fuel pump would be nice after getting it set-up. I would run headers on the Chevy but manifolds if I go Olds.
Opinions are appreciated for which engine would be better and why. Thank you.
Olds
I have a stock ‘73 short block. Number 5 heads. Roller tip rockers. I want to fill the heat risers. Also a valve job and flat tappet cam and spring kit.
Vortec 350
Basically stock with a cam and valve spring upgrade. .475” or so lift to avoid machining on the Vortec heads. I would buy an engine from a wrecking yard.
The pro that I see with the Olds is I won’t need to worry about an electric fuel pump and return line. But with the Chevy I will have the advantage of a roller cam and more efficient heads. I figure the electric fuel pump would be nice after getting it set-up. I would run headers on the Chevy but manifolds if I go Olds.
Opinions are appreciated for which engine would be better and why. Thank you.
Last edited by VinMichael; October 1st, 2018 at 06:27 PM.
October 2nd, 2018, 10:56 AM
#5
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I would go with vortec 350, add the compcam beehive springs (no machining needed), new GM lifters, self adjusting roller rockers and GM LT Hot cam. Just finished one few weeks ago and put it in my friends Impala, runs great with plenty of power to move the behemoth. Total cost was about $1500 and that's including the engine, new fuel lines and electric fuel pump. According to Hot Rod Magazine that combo puts put little over 400hp/400lb.tq.
October 4th, 2018, 05:59 AM
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December 22nd, 2018, 06:59 PM
#7
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So here is what I ended up with for the El Camino so far
4 bolt main 350 010 block
line honed and bored 60 over
flat top pistons
Eagle i-beam rods
stock crank turned 10 under
balanced
Edelbrock E-Tec 170 heads - springs are for a hydraulic FT
RPM airgap
holley 750 vac secondary
the plan now is to zero deck the block to achieve 10 - 10.25:1 compression
i am sort of stuck with deciding on the cam. I already have the 2,000 stall converter and want to keep drivability very good. And I don’t want to over-cam with this stall.
I suppose i can be talked out of using this 2,000 stall converter, but I already have it and I like how it performed when I had it paired with my Olds 350 with generic RV cam.
Also im concerned about under-camming with the planned compression ratio and 91 octane
any advice is appreciated. I just reallly don’t want a soggy bottom end. I want torque and throttle response off idle to 6,000 RPM. I want to drive this car regularly, even in traffic etc. .
4 bolt main 350 010 block
line honed and bored 60 over
flat top pistons
Eagle i-beam rods
stock crank turned 10 under
balanced
Edelbrock E-Tec 170 heads - springs are for a hydraulic FT
RPM airgap
holley 750 vac secondary
the plan now is to zero deck the block to achieve 10 - 10.25:1 compression
i am sort of stuck with deciding on the cam. I already have the 2,000 stall converter and want to keep drivability very good. And I don’t want to over-cam with this stall.
I suppose i can be talked out of using this 2,000 stall converter, but I already have it and I like how it performed when I had it paired with my Olds 350 with generic RV cam.
Also im concerned about under-camming with the planned compression ratio and 91 octane
any advice is appreciated. I just reallly don’t want a soggy bottom end. I want torque and throttle response off idle to 6,000 RPM. I want to drive this car regularly, even in traffic etc. .
Last edited by VinMichael; December 22nd, 2018 at 07:05 PM.
December 22nd, 2018, 07:50 PM
#8
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Michael,
I would wait till after Xmas and call a couple of the camshaft companies and ask them. They are the ones that know their products and what works in a particular application. Unless someone else has the same exact engine/vehicle combination as you they are just guessing. I have been building engines for over 30 years for a living and I still don't try to pick a cam by myself. Edelbrocks cams are actually pretty decent but they only have a couple of choices for each engine family.
I would wait till after Xmas and call a couple of the camshaft companies and ask them. They are the ones that know their products and what works in a particular application. Unless someone else has the same exact engine/vehicle combination as you they are just guessing. I have been building engines for over 30 years for a living and I still don't try to pick a cam by myself. Edelbrocks cams are actually pretty decent but they only have a couple of choices for each engine family.
January 15th, 2019, 09:34 AM
#9
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Location: TEXAS
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Easy answer is the L31 Vortec, best little OEM 350 around as is. I have done a few and a buddy even pulled his own 280k mile out of his old 97 suburban, merely washed it an swapped it to a carbureted intake and headers with not even a valve cover removed and left even the truck roller cam stock , dropped it into his 82 GMC 1/2 SWB and it runs great, no smoke at all , not rattles and easily smokes the tires.. Runs great. I had a local Dallas rebuilder freshen up my old 93 350 block 030 and let them use there very low compression below deck dish pistons and bought remanufactured 96-2000 vortec heads to put on it making it under 9:1 along with a Elgin knock off of the old Crane 218/218 .450 .450 106 cam (3/4 LOL) , used ZZ430 intake (like a RPM) and cheap headers, that with a only a 12" 2500 and 3.73 gears in his long bed 74 C10 and went 9.0 in the 1/8
January 15th, 2019, 10:47 AM
#10
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I ended up going with this cam based on Lunati's recommendation
Part Number: 10120702
Previous Part Number: 60102
- Advertised Duration (Int/Exh): 262/268
- Duration @ .050 (Int/Exh): 219/227
- Gross Valve Lift (Int/Exh): .468/.489
- LSA/ICL: 112/108
- Valve Lash (Int/Exh): Hyd/Hyd
- RPM Range: 1400-5800
- Includes: Cam Only
Part Number: 10120702
Previous Part Number: 60102
January 15th, 2019, 12:00 PM
#12
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Another old example of L31 power about 15-18 years ago I friend was needing to get his old 57 Chevy 210 4 door hard top street car going again. It had a good 350 flat top short block in it and a Muncie 4 speed and a 3.73 8.5 10 bolt rear. I suggested the Vortec L31 heads and a RPM intake along with that he went with the cam I recommended at the time a Comp 275DEH 219/229 110 / 106 .462/ .482 as a friend with a set of Trick Flow twisted wedge heads on a flat top 355 in a 80 Malibu had been running very well with one. He got the 57 going with that set up and even went to Ennis once for the 1/4 mile and managed a 12.8 which was impressive especially since the older 4 speed set ups usually run slower ET than a high stall automatic car .. Later that engine got pulled and put in a 79 Malibu Wagon budget drag car that had 4.10s and the 8.2 or so 1/8th of the 57 improved to a 7.6 in the automatic wagon which is close to 12.0/11.9 in the 1/4 and that is the God's honest truth and no altitude corrections. The actual ET with 1.94/1.5 valve L31 head on a 355 and cam flat tappet hydraulic cam at .462/.482 with 1.5 rockers. I ran those type heads on a flat top 406 SBC in a S10 and went 11.48 with a 7.26 in the 1/8 but it was lighter than their stuff. Small valves also and under .500 hyd flat tappet as well.
January 15th, 2019, 12:31 PM
#13
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Yes, that would be a very good pairing, but the cam you chose will be significantly different than the RV style cam, so the converter needs to match the new cam. The 2000 RPM converter will work, but it may be slightly sluggish off the line.
January 15th, 2019, 02:46 PM
#14
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My car has a 2500 stall and it drives very nicely, as in you wouldn't know it has that high of a stall until you go WOT from a stop.
Yes, that would be a very good pairing, but the cam you chose will be significantly different than the RV style cam, so the converter needs to match the new cam. The 2000 RPM converter will work, but it may be slightly sluggish off the line.
Yes, that would be a very good pairing, but the cam you chose will be significantly different than the RV style cam, so the converter needs to match the new cam. The 2000 RPM converter will work, but it may be slightly sluggish off the line.
You are right the RV cam I am referring to is quite a bit smaller
Intake: Valve Lift: .448 Duration: Dur. @ .050: 204°
Exhaust: Valve Lift: .472 Duration: Dur. @ .050: 214°
Difference between lobe centers: 112°
Another old example of L31 power about 15-18 years ago I friend was needing to get his old 57 Chevy 210 4 door hard top street car going again. It had a good 350 flat top short block in it and a Muncie 4 speed and a 3.73 8.5 10 bolt rear. I suggested the Vortec L31 heads and a RPM intake along with that he went with the cam I recommended at the time a Comp 275DEH 219/229 110 / 106 .462/ .482 as a friend with a set of Trick Flow twisted wedge heads on a flat top 355 in a 80 Malibu had been running very well with one. He got the 57 going with that set up and even went to Ennis once for the 1/4 mile and managed a 12.8 which was impressive especially since the older 4 speed set ups usually run slower ET than a high stall automatic car .. Later that engine got pulled and put in a 79 Malibu Wagon budget drag car that had 4.10s and the 8.2 or so 1/8th of the 57 improved to a 7.6 in the automatic wagon which is close to 12.0/11.9 in the 1/4 and that is the God's honest truth and no altitude corrections. The actual ET with 1.94/1.5 valve L31 head on a 355 and cam flat tappet hydraulic cam at .462/.482 with 1.5 rockers. I ran those type heads on a flat top 406 SBC in a S10 and went 11.48 with a 7.26 in the 1/8 but it was lighter than their stuff. Small valves also and under .500 hyd flat tappet as well.
January 16th, 2019, 06:01 PM
#15
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I don't think I have ever really drove Vortec powered trucks, at least not pushing them hard. Do they have more low end than the garbage swirl port 350's and 5.3 LS? Those Etec heads have very close to the flow of 1.92" intake Ram EQ magnum heads on my Dakota. With a 2.02 intake the Ram EQ heads equal Procomp Olds heads with the same 170cc runner as the Vortec. I just need the injectors firing at the right time and cam would really move it and probably leave the 42RE on the ground. What gearing are you running? That 2000 stall may flash higher and work OK.
January 17th, 2019, 07:10 PM
#16
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The L31s are just solid running engines and are a dime a dozen. I didn’t like the 5.3 when they cam out and still don’t. I just like how the older style 350s run even if they are not “as good” as the 5.3.
I also like the dodge magnum 5.2 and 5.9 a lot. Although I’m not in a hurry to go back to those older engines after getting a vehicle with a 5.7 HEMI.
For the El Camino, I’m planning on 3.73 years. Although I’m starting to like the the idea of 4.11 gears more and more.
I also like the dodge magnum 5.2 and 5.9 a lot. Although I’m not in a hurry to go back to those older engines after getting a vehicle with a 5.7 HEMI.
For the El Camino, I’m planning on 3.73 years. Although I’m starting to like the the idea of 4.11 gears more and more.
January 17th, 2019, 07:21 PM
#17
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Other than some spider injector issues it sounded like the L31 was an all around better motor than the earlier TBI, which were gutless. Other than the Gen 5 5.3, I think the 5.3 is a no bottom end turd. The Magnum heads all crack, just depends on how bad. Also the plenum with a crappy steel plate with bolts too long worked just like it sounded. I got the thick aluminum plate and new bolts. Good luck, it should be a fun build.
Last edited by olds 307 and 403; January 17th, 2019 at 07:24 PM.
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