[mikeweyman]

I looked at a set of heads yesterday casting # 354434 65cc chamber 202 intake 160 exhaust
intakes and bowels are ported , exhaust not ported.stainless valves,bronze guides .
that are , i was told may be off a 1977 - 305 h.o.probably off a monza.
my motor is a 1975 4 bolt vette engine with
stock 76 cc 202 int. 160 exh.882 casting (L48)
8.5-1 compression 165 h.p.
does anyone know what if any will be the increase in hp.,compression,etc.
what are they worth?? any help is greatly appreciated. mike. <img src="graemlins/mwink.gif" border="0" alt="[mwink]" />

[mikeweyman]

THE BOTTOM END IS STOCK WITH 57,000 MILES MY BUDDY SAYS THEY'LL BLOW UP THE ENGINE, COMPRESSION TOO HIGH. ANY TRUTH TO THIS??

[willys36@aol.com]

Usually not a good idea to put fresh heads on a tired bottom end. Good chance of overstressing it.

[Ohio-Dan]

A 354434 is a 262/267/305 head, used '75-'79 with 60cc chambers. Stock, they had 1.72"/1.50" valves. Are you sure they have a 2.02" intake? Although I don't know that casting for sure, most 58-60cc chambers will be getting real close to water when opening them up to fit big valves. A 1.94" is the biggest I have seen used with a 305 casting.

As far as air flow goes, my money is on the 882 out flowing the 305 casting. Even a ported 305 casting will have a hard time flowing 200cfm on the intake side.

Compression ratio; A 65 cc chamber will raise you compression by about 1 point. If you put the motor back together using a thick Fel-Pro gasket you will only see about a half point increase. Your motor came stock with a thin steel shim gasket. Either way a 1/2 to 1 point increase in compression isn't going to be that hard on a motor. The 4% power increase per point of compression increase is about right.

Power; You will get an increase in bottom end power, with a bit of loss in the top. If you have future plans of bigger cams and such, there are better choices than a 305 casting.

The last set of 601's I bought where $340(US). 1.94"/1.50", 3 angle, bronze guides, Z-28 springs, etc. (I run them on a 305.) Dan

[mikeweyman]

the heads were remanufactured by Indy head in california,the spec on them is as follows,
G.M. heavy weight castings,3 angle valve job,bronze wall liner,aeromax stainless steel polished valves ,202 int. 160 exh.new umbrella seals,locks, retainers,springs are suitable for up to a 525 lift cam,3/8 screw in studs,65 cc chambers,pockets and intakes ported and polished.
they were bought from summit racing for 1,200.$
american,believe it or not.i,m glad it wasn't me..

[nicefrog]

Hi, I have one of these heads, strange thing having just one head but I bought it for porting practise along with a single #185 head, so if you ever break a 434 you know who to see : ). They have smaller ports and valves than the 416 castings I ported for my 305, but there is enough metal in the ports to go as big as the 416's if you wanted to. The roof of the exhaust ports looks dodgy to me, I can't see the point in having ported inlets and not doing the exhaust port. The exhaust looks similar to the stock 416's so they should be ported if the inlet is allready done. The 2.02 valves should fit but it would be pushing the limits. The heads you've got are allready the good stuff with big valves, I think you would be better porting the heads you have enless you really want alot more compression