Gen 1 LT1 Intake manifold

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Gen 1 LT1 Intake manifold

Postby jaloi » Wed Nov 29, 2017 4:05 pm

My Vega's got a '70 1st Gen LT1 in it.I'm putting it back to original specs or as close as I can get.The bottom end is fine,still has the forged flat tops and the holes look good,can still see the cross hatch from the hone.Someone had 624 heads with 1.72/1.50 valves and a Torker 1 intake with a 600 Eddy carb.Putting the 461 heads with 2.02/1.60 valves and the 780 Holley it was supposed to have but wondering about the intake manifold.I know the original 3972110 manifolds are out there if you wanna spend a grand on a used one but wondering if there's anything that works as well or better than those.I'm running a 250 shot of nitrous so probably be looking for a single plane square bore. Any suggestions? Thanks
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Re: Gen 1 LT1 Intake manifold

Postby Smiley » Wed Nov 29, 2017 5:23 pm

Edelbrock RPM airgap 7501
they run about $260 new online
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Re: Gen 1 LT1 Intake manifold

Postby spencerforhire » Wed Nov 29, 2017 6:51 pm

The only reason to cough up the big $$$ for one of those original "Winters" aluminum intakes is if you actually have a 1970 Corvette/Camaro Z28 and need it to be correct to sell it at the Barrett-Jackson auction. That Edelbrock Air-Gap will out-perform the original at all RPM levels.
The "fleet"-
77 Vega Estate wagon- project(someday)will have TPI305/T-5, S-10 spindles/axles
72 Vega HB Drag Car -383/'Glide/9"(9.35@146.19)(5.94@117.28 1/8th)
76 Vega GT- 400/4spd/9" retired from active duty(rusty)
03 Silverado 2WD ex.cab (work truck/parts hauler)
04 Silverado 2WD ex.cab (retired)
06 Haulin' 20ft enclosed car transporter
93 Suburban- 350/4L60(retired)
00 Saturn SW2- wife's car
01 Saturn SC2- younger son's project
00 Saturn SL2- daughter's car
98 Saturn SW2- spare
and 3 more Saturn "parts cars"
Note- the very act of listing all of these has made me realize I have some kind of problem.....

Visit http://www.spencerforhire.ca
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1972 Chevrolet Vega Hatchback

Re: Gen 1 LT1 Intake manifold

Postby T-FATTY » Wed Nov 29, 2017 7:25 pm

Weiand Stealth intake if you can find one. No longer made but I got a NOS one on ebay for m Z28.
YES I accept paypal donations...
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Re: Gen 1 LT1 Intake manifold

Postby jaloi » Thu Nov 30, 2017 12:18 am

Thanks guys,I did some research and that does look like a good manifold for my application.The closest match to the 3972182 cam is the Hpward's American Muscle, Mechanical Flat Tappet, Advertised Duration 316/336, Lift .459/.485. I'd kind of like to go hydraulic but any cams with that lift are all roller tappet.Not sure I can handle the added expense on this build unless someone knows of a hydraulic flat tappet that will perform as well.atarying to get her back to the 370hp it once was...
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Re: Gen 1 LT1 Intake manifold

Postby Smiley » Thu Nov 30, 2017 2:47 am

COMP Cams Thumpr Hydraulic Flat Tappet Camshafts 12-602-4
COMP Cams Thumpr Hydraulic Flat Tappet Cam and Lifter Kits K12-602-4 with lifters,springs,retainers and timing chain.
Hydraulic Flat Tappet, Advertised Duration 295/313, Lift .500/.486, Chevy, Small Block
the correct springs may require machining the valve pockets.
Comp suggests having the cam nitride treated and using the lifters with the lobe oiling hole.
Always use a zinc additive for all flat tappet cams or run the hot rod type oil for classic cars still has the zinc needed for flat tappets.

Crane 114571. Camshaft, Hydraulic Flat Tappet, Advertised Duration 308/316, Lift .495/.510,

They make longer duration hydraulic specialty cams if you can handle lift over .500"
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Re: Gen 1 LT1 Intake manifold

Postby MonzaRacer » Sun Mar 11, 2018 6:58 pm

first of all 461s will not have nessesary bolt holes in cylinder head for a 70's 350 LT1 and double humps were not sold in 70 except over the counter. With flat tops this will push you to 10.1 to 1 or more and I sure as heck would not hit a stock block 350 even old forged engine with 250 shot.
For the record your engine would be better off with a better head like 202/160, 441s as those could be had on Corvettes with 202/150 and decent cam.
As for that intake, shelve it and step up to at least mid 70s technology. BUT my buddy has a very sweet 383 in his 66 Nova SS with edelbrock heads scat/JE bottom end and a 250 shot.
As a tuner I have seen so many supposedly solid bottom ends scattered by "just a 250 shot" and stock GM pink rods wont take that for long even with progressive controller.
And unless you pull pistons and open up compression ring gap you chance busting ring lands and had better have some good fuel and tight watch on timing.
Last edited by MonzaRacer on Sun Mar 11, 2018 8:46 pm, edited 1 time in total.
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Re: Gen 1 LT1 Intake manifold

Postby Smiley » Sun Mar 11, 2018 8:36 pm

In a V8 Vega swap, 461 or fuelie heads work fine as you must run a short water pump and there are alternator brackets that do not need the holes in the heads.
The 1970 LT-1 350 would have had 3991492 heads, Camel hump,drilled for accessory holes,64cc, straight plug.
1971 and later they were over the counter.
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