Picking out heads.

[SimpleGreen]

So, Ive been kicking around buying new, assembled heads for my V8 swap vs getting my old ones done up.

The machine shop fella said for around $400 he could machine my heads for 2.02/1.60 valves, hog em out some, all that fun stuff, in addition to the usual things that would be done when redoing a set of heads. I would have to supply things like valve springs, valves, etc at an additonal cost. I figure the heads would end up around $600-700 in no time flat.

I investigated some heats on Summit Racing, and started looking at their own set.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D152123&N=700+400304+4294925232+4294838998+4294867081+4294 840140+4294924746+115&autoview=sku

They have 2.02/1.60 valves, ARP screw in studs, 1.250 springs, etc @ $650 for a pair.

Would those be fine in a hydraulic roller setup? It also says that the max lift is .520. My ZZ4 cam is rated to .501. Is that too close?

Would it be worthwhile to pick up something like this and switch to a non Vortec style intake manifold?

Any words appreciated.

[bored&stroked]

Would it be worthwhile to pick up something like this and switch to a non Vortec style intake manifold?


If your switching from a vortec intake then you already have vortec heads?

[GreaseDog]

runner size would concern me a little more than valve size.

[SimpleGreen]

runner size would concern me a little more than valve size.

Runner on the Vortecs is 170cc. Runner on the heads in question is 165cc.

I read up runner sizes. And from what I gather, that 5cc isnt much worth worrying about given the circumstances.

[gmc406]

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D152123&N=700+400304+4294925232+4294838998+4294867081+4294 840140+4294924746+115&autoview=sku


I don't see any flow #'s on those heads.

[GreaseDog]

hmmm...
http://store.summitracing.com/partdetail.asp?part=SUM%2D151124&view=1&N=700+150+

[GreaseDog]

http://www.chevelles.com/forums/showthread.php?t=178815&highlight=152123+flow

that's all i have found on them so far. for a fully assembled price, they dont sound too bad, especially for a truck head.

[Red94Chev]

Besides making sure the heads are a direct bolt-on, the most important factor in choosing a good performance head is the head flow data and combustion chamber size. Your stock heads are 64cc versus Summit's 67cc. You'll lose a few tenths in compression and this may nullify the performace benefit of better flowing heads over the stock units.

I have Trick Flow 195s (62cc) on my truck and they're a great aftermarket aluminum head for the money. I probably would have bought the Trick Flow 175s if they were out when I bought my heads. They are comparable to the performance of Edelbrock's excellent Etec-170s. but have 56cc combustion chambers. That will put you at ~10.1:1 compression for a bolt-on. Better performance in two ways: increased compression and better flow. Three ways if you count weight savings of about 50 pounds. Match a decent camshaft (Comp's XE262 comes to mind) and low restriction exhaust and you'll have a real performer then and still run on pump gas. Of course, you'll need tuning as well. The fully assembled entry level version of these heads start out at under $1000. A good deal in my opinion.

[GreaseDog]

the combo you just mentioned sounds good for a daily driver, but the cam is a little soggy down low, and would require a small stall converter to take full advantage of its powerband. i wouldnt be a bit surprised if those heads fell flat on their face well before the cam did.

what are you looking to accomplish with this swap?

[SimpleGreen]

the combo you just mentioned sounds good for a daily driver, but the cam is a little soggy down low, and would require a small stall converter to take full advantage of its powerband. i wouldnt be a bit surprised if those heads fell flat on their face well before the cam did.

what are you looking to accomplish with this swap?

This wont be just some head swap on some TBI 350. Its in addition to a completely bored/rebuilt carbed (Holley 600 4160) Vortec 350 V8 witha GM ZZ4 cam. Most likely then dyno tuned.

Oh, and I have a converter for the transmission (TH400), a TCI Saturday Night Special 2200 stall that I recieved in a trade.

The truck is just for enjoying on the weekends, maybe tow a few things (nothing major), etc. Its not a daily really.