z28inhurtlocker

ok i have a 1984 z28 with a 76 305 in it one of the rocker studs snapped out of head and my heads are now shot. I have a set of heads from a 350 out off a 1995 and wondering if i were to try to put those heads on would they line up. would it increase or lower horsepower if so by how much. Is their room between pistons and valves would they hit. or would they work just fine. the motor also has a edelbrock performer intake manifold, edlebrock carb, and high performance exaust. Help me please!!!!!!!!!

redneckgames

Yes they will bolt on and run.

Depending on what casting number they are, and the ones you had are, you may lower compression.

Dont expect any more power. If compression is lowered, you may lose a bit.

(all that is assuming you have the stock cam in the 305)

z28inhurtlocker

how do i find the casting numbers. i'm 18 and have just recently started working with cars up till now my passion has been snowmobiles. just trying to gain some extra knowledge. and also when i ran the vin myself it said the motor was a 76 305 but i may have done it wrong is there an easier way to figure that out?????? thanks

z28inhurtlocker

also i love your collection of vehiclesi currently have
1984 z28 camaro and a
1989 z28 camaro
that i'm gonna make into one
also i just bought a 1986 chevy S10 with a 350 dropped into it but the tranny went ca----put so i'm in the middle of getting that fixed
and also i have a 1971 cutlass supreme with a 350 rocket in it with 86,xxx original miles and besides me it has had only one previous owner with minimal rust just the paint is faded

88 Iroc: 97 Vortec 350 w/lt4 hot cam, A4, 3.73 1/8: 8.50 & 74 mph
85 S10: 350/350 combo, Dart 200P Pro1s, 10.5:1, Lunati 40150 244/249 @ 50 .565/.543, Air-Gap, 650 DP
67 Chevelle SS: 396, 4 speed, 3.73, Flowmaster 40s

jloshotz

Definitely do your homework before bolting them on. I had a buddy that put a pair of 350 heads on a 305....his compression was so low that the motor would barely run at all. Felt like it had about 145 horsepower when it went down the road. I'd try to hit a junkyard and replace them with the same heads. Just my .02

cnorton

I'm not clear on the source of the 1995 350 heads? If they're from a 1995 Camaro or Corvette, they will NOT work on your 305. Reverse flow heads from 1995 will bolt onto the block but there is no way to match up the water jackets.

If the1995 heads are from a truck, they will fit the block but will probably do nothing to enhance performance (see the response related to compression).

We need a bit more detailed information.

quickchicken

quite a few years ago Car Craft did an article on a 325 hp 305 and they used 350 heads but the had them milled down, if your willing to do this then they will work but will req a cam to get them to work well.

Z28SORR

You said it was a 76, 305 and the numbers say it's a 76, 305. So it looks like you did it right.

If you want 350ci. hp put a 350ci. in it. It's not hard and 350's are a dime a dozen.

quickchicken

how many miles on the 305 short block? if its the milage isnt too high just have a machine shop machine the bosses and have screw in studs put in and have the valves cleaned up then put it back together.

chevy_dude97

just threw out a set of 305 heads from a 92 camaro....
The rocker studs are press fit, you can yank em yourself if you get the tool.
Then drill/tap em for screw in studs... I do believe we found heads for the car cheaper on craigslist already ready than to have the local machine shop do em, hence threw away. Good luck on your build...

byrons1502

Most 305 heads are 76cc. It is very hard to find tight chamber 305 heads. Most of them came on the hi-po 305, monte ss and hp camaros plus some more. the heads are probably both 76cc or larger. I have found most 305 heads measure around 80cc because of the small valves and they sink alot very quickly because no one maintains them.

quickchicken

87-90 LB9 081 305 casting heads are 58cc chambers.

ws6transam

Be patient and you can probably find a set of 305 heads for FREE. Something from the ealry 80's would bolt onto your 1976 engine block just fine and be much better than the mid-70's 305 heads. Like Richard said, the 80's 305 heads were 58cc. One of the tricks that Summit Racing Equipment used to do in the early 90's was to buy 305 heads, install a bigger intake and exhaust valve, clean them up in the ports and re-sell them in their catalog for mild performance upgrades for 350's. We don't do that anymore 'cause there are cheaper ways to go about it unless you have machine access and time.

I once did a 262 RWHP 305 engine for my car, and did it with some 1987 305 heads with a 1.94 intake valve that I ported extensively. If you have a die grinder, the SA abrasives porting kit and an air compressor you could do the same thing but expect about 24 hours of grinding time to get the same results, unless you are experienced. I had about $250 into the heads when finished....

Porting the GM 305 Cylinder Heads