Would the Sportsman II heads work on a 305 if they were milled, assuming the 305 already has a good exhaust, intake system, and a good cam.

Jon

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82 Trans Am
Original 134,000 mile LG4
Holley 600 cfm carb, Weiand Stealth Intake manifold, no smog equipment, Hooker headers are in a box next to the car, and some true dual exhausts are gonna be fabricated soon, hopefully....

 

Jon,

You would have to watch valve lifts very closely to prevent slamming the deck with a valve. The SIIs probably have at least 2.02/1.60" valves, which are too large to clear the bores of a 305 at any appreciable lifts. You could mill or flycut clearances in the deck, but by the time you were done, you would lose compression to the larger chamber sizes. Overall, you would spend a lot of time and effort to get marginal results.

There are better choices for 305 heads that should make more power than the SIIs. However, if you have a set that is available at a really good price, you might want to grab them for a future 4" bore block.

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Later,
Vader
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"What a Day..."
Adobe Acrobat Reader

 

Hey, thanks for the advice, vader.
Well, since there are other options that are available, can you help me out? The World Torquer heads don't seem to bring that much in the area of results... and I already have my intake put in, so i don't want to go the Vortec route... got any advice?

Thanks a lot, man
Jon

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82 Trans Am
Original 134,000 mile LG4
Holley 600 cfm carb, Weiand Stealth Intake manifold, no smog equipment, Hooker headers are in a box next to the car, and some true dual exhausts are gonna be fabricated soon, hopefully....

 

Well I'm not Vader, but the WP S/R Torquers flow more on the intake than L98 Vette heads. Their major downfall is on the exhaust side, here they don't even flow as good, in fact they flow about 30 CFM less than the L98s on the exhaust side.

Aside from the SR Torquers, you options are limited to heads with smaller combustion chambers and smaller valves. The L98 heads will fit, but then you run into emission legality problems. The L98s don't have the built-in EGR passages, so you'd have to plumb a line from your headers just like the Corvettes do.

Other than those two heads, your options are limited. The Edelbrock performer heads will work with the smaller bore, but only up to .450" lift, then you run into valve-to-bore interference like Vader was talking about.

It's tough to pick some great cylinder heads for a 305, but hey, the ZZ4 puts out 355 hp and uses the L98 heads, so maybe they're worth checking out. Maybe with some exhaust side porting and polishing the SR Torquers will hold up to that number too.

Jason

 

I suppose that I should have mentioned that I have no emissions requirements here (good ole' wisconsin). Why not just through in a 350? Well, this is a daily driver, and will never see track duty... I just want to drive it to work/school and win a couple of stoplight wars. So, the L98 heads are good? And the Torquers are good, if I get the exhaust side ported... ok... any more ideas keep comin... in the mean time, i'm gonna check some prices on those L98 heads.

Jon
PS, has anybody tried the Torquers after modifying the exhaust side?

 

You will see a significant increase with the Torquers. Just do a little bowl work and work on the exhaust side and it will help quit a bit.

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350 4 bolt main, Speed-O-Motive 383 stroker kit, re-sized rods ground for clearance,TRW Forged pistons,10.7:1 compression,HPC Coated RPM intake, Speed Demon 750 cfm carb,World Products Sportsman II heads,2.02/1.60 valves, Comp Cam 1.6 roller rockers, Comp Xtreme 284 cam,240/246@.050 with .540 lift,Crane pushrods,ATI damper,Proform HEI and MSD6A box,HPC coated 1 5/8 headers, 2.5" exhaust with 40 series mufflers,TH350 with Hughes 3000 stall, Powertrax NoSlip Locker, 4.11 gears.