SSC

I was looking up the casting numbers and came accross lt1 71-72 76cc for the heads "3973487" These heads dont look special so what are the advantages? since they are Lt1 did they come off a vett?
The block isnt very special "3970010" 72-81 4 bolt, but do you think these make a good match up?
SSC

ede

the LT-1 was put in vetts and z28s when they camaro went form 302 to 350. i don't know for sure but i suspect the lt-1 heads were smaller chamber but maybe not, 11:1 pistons, winters bros foundry aluminum intake, holley carb, 4 speed gear box. i ithnk 350 hp in the f body and 370 in the vett. i think the exhaust manifolds were differant to make the hp, plus gm didn't want the f body to make more hp than the vett. the block would be the standard casting 4 bolt with a steel crank and i think a solid cam.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

SSC

Thanks for the info Ede! Its to bad this setup needs to run on 85 octane. It seems to be way easyier to make somthing thats fast than somthing that gets good mileage. Oh well its good to have the numbers written down and reasearched before they go to the machine shop.
SSC

Ughh, I must have been tired.



[This message has been edited by SSC (edited October 12, 2001).]

five7kid

iTrader: (14)

They should have angled spark plugs, 2.02/1.60 valves, screw-in studs. I once thought they were 64cc, but I believe 76cc is correct. With flattops you should be able to live with our fine Colorado 85 octane regular unleaded gas.

I had a set on a 302 (yes, a 327 block/283 crank SBC 302) with 12.5:1 TRW's and the LT1 solid lifter cam (310-range advertised duration). No guts below 2500 RPMs, but above that you just hung on and tried to keep breathing.

I believe the f-body version was rated at 360 HP, mostly to keep it below the Vette like Ed said.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

jms

iTrader: (1)

I've used many sets of 487s on street engines and most came from 1971-73 regular 350s from Impalas, Caprices, and Chevelles with 4-barrel engines. 1.94 intake and 1.5 exhaust valves with pressed in studs.

There were 487 and 487x versions. In the late '70s, the x versions were considered to be slightly better.

Not bad heads as far as 76 cc'ers go but nothing special either.
jms

iroc22

I thought that in '70 the vette and camaro were both 370hp but then the camaro received the drop in compression for '71 making it 350 hp and the vette retained the compression

jms

iTrader: (1)

The 350 LT1 'Vette rating in 1970 was 370 hp at 6000 rpm with 380 lbs torque at 4000 rpm.

The Z-28 LT1 in 1970 was 365 hp. Remember, GM did not like to have anything rated more than the 'Vette although they said the exhaust was a little more restrictive in the F-Body. Sound Familar?

The LT1 in the 1971 'Vette was 330 hp at 5600 rpm (torque was 360 at 4000 rpm)due to a change in compression (9:1 vs the '70's 11:1). Most of Detroit was getting ready for the unleaded gas requirement that was due to be in effect in 1974.

In 1972, the method for rating power was changed and the LT1 was then rated at 255 hp at 5500 rpm with 280 lbs torque at 4000 rpm.

The Z-28 was always a few horses less than the 'Vette.
jms

SSC

They are straight plugs so nothing special 1.94, 1.5. It just freaked me out when mortec said "LT1." The shop will go through it in a couple of weeks and give me the 411 on what the engine will need. I think I'll just have em bore it .30 and completely go through the heads, new guides and such.
Thanks for the info guys!
SSC

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85 Camaro, 355/400 "drag car" in moth ***** 13.1@ 101mph on its last season run.
Plans: Possibly add N20 for next season.
82 Firbird, getting a beef injection 355/700r4 3:42 powertrax system.