R.O.B.

Does anyone have the headflow data for stock 350 heads?
Are they 64cc heads?
If they are 64cc, do you think they could be milled to work as a cheap alternative on a 305?

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Rob
'86 TA 305 TPI
Gutted MAF
Ported Plenum

Digger

Im pretty sure they are 74cc heads

R.O.B.

Lucky for the 350 guys, most aftermarket heads are 64cc, nice compression jump for them.

Anyone else know?

------------------
Rob
'86 TA 305 TPI
Gutted MAF
Ported Plenum

Mark305TBI

GM 882 151cc Intake 76cc Chamber
Lift Intake Exhaust
-------------------------
.100 70 59
.200 125 109
.300 175 136
.400 204 204<-This one don't look right
.500 205 143
.600 206 145

These numbers came from this listing of head flow charts.

-Mark W.
'88 SC Camaro w/ 305 TBI

R.O.B.

I saw that same list. I wasn't sure about the 76cc part. Is it correct?

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Rob
'86 TA 305 TPI
Gutted MAF
Ported Plenum

ws6transam

The 882 heads are indeed a 76cc chamber. they are better known as "Mid-70's, thin casting, prone-to-crack, smogger heads."

They are an open chamber design an as such, you can install 2.02 valves without much problem. However, be sure to port the bowl afterwards or you'll be actually stepping backwards with airflow.

Read Lingenfelter's book. He's pretty down on the 882's. You will NOT want these heads for a 305!

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Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
New best E/T! 14.039 at 100.82 MPH in 41 degree air at Stanton, Michigan.

R.O.B.

Didn't the thirdgen 350's come with these heads?

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Rob
'86 TA 305 TPI
Gutted MAF
Ported Plenum

burnoutrpm

i have these wonderfull heads and yes theyre complete crap! 76 cc ido have the 202 160 valves! and jhon L. is right tthey suck! bad! no, they didnt put them on any 3rd gens from the factory! g.m. was smarter than that! they put real heads on the 350's..ok well... better heads!

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 and a 600 edlebrock manual choke.

Future mods performer rpm air gap intake (polished) comp roller cam, and way better headsa 400 defintely in the works!

AlkyIROC

You can't put 202/160 valves in them and expect it to work on a 305. The valves will hit the sides of the block.

Go find some 993 or 997 castings. They're also 76cc chambers but are much better castings. Using flat top pistons and having the block zero decked will give a good compression ratio. You can use dome pistons to increase the ratio even more.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley