Will this help???
Thread Starter
Junior Member
Joined: May 2001
Posts: 55
Likes: 0
From: Canada
Car: 1987 Camaro
Engine: 305 LG4 Carb. (no ECM)
Transmission: TH700-R4
Will this help???
I plan on slowly building up my '87 LG4, and I was thinking about building up some 350 heads and putting them on the engine. I'd really appreciate if someone would tell me whether they would fit (heard something about '87 305s having different bolts or something? 
), and whether or not there would be a performance increase over top of the stock 305 heads.
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1987 Camaro Sport Coupe
305ci 4bbl (LG4)
3.23 Gears
THM 700-R4 Automatic Transmission
All Stock
), and whether or not there would be a performance increase over top of the stock 305 heads.------------------
1987 Camaro Sport Coupe
305ci 4bbl (LG4)
3.23 Gears
THM 700-R4 Automatic Transmission
All Stock
Joined: Mar 2000
Posts: 43,187
Likes: 43
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
The biggest issue is the chamber size, which is smaller on 305's meaning 350 heads will lower your compression significantly. Although they might flow better than your 305 heads, you'd lose any power gain that might produce because of the lower compression.
What engine do you plan on having in the end? If you're sticking with the 305, then air cleaner, exhaust, cam & heads, in that order, are what should be improved. Pocket ported World Products 305 S/R Torquers are the ticket for the heads. Everything but the heads will also work on a 350.
If you want to have a 350 when you're all done, then go ahead and build up some 350 heads, but don't bolt them on to anything but a 350.
There are some year-specific issues with heads like center intake bolt angles and perimeter or center-bolt valve covers, but those issues exist with both 305's & 350's, not that they're different between a 305 and a 350.
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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, 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).
What engine do you plan on having in the end? If you're sticking with the 305, then air cleaner, exhaust, cam & heads, in that order, are what should be improved. Pocket ported World Products 305 S/R Torquers are the ticket for the heads. Everything but the heads will also work on a 350.
If you want to have a 350 when you're all done, then go ahead and build up some 350 heads, but don't bolt them on to anything but a 350.
There are some year-specific issues with heads like center intake bolt angles and perimeter or center-bolt valve covers, but those issues exist with both 305's & 350's, not that they're different between a 305 and a 350.
------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, 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).
