Grandview IROC Z

I plan on installing a 383 stroker in place of my L98. My heart says the cast steel vortec heads will suffice and there is not that much difference in cost to get the aluminum heads on a blueprint crate engine long block. I intend to install the First Performance TPI system on which ever engine I decide to purchase. Is there really that big an improvement with going with alum heads? I will be doing weekend street driving and an occassional auto cross with my 89 IROC, and hope to drive the car another 100,000 miles without issue

ShiftyCapone

iTrader: (7)

Each has their respective benefits but if the cost is similar chose the head the flows the most (assuming port size, CR and valve size is the same). Which aluminum heads are they?

dmccain

iTrader: (2)

You shave some weight with aluminum and the prices on some of them like procomps, blueprints, or Summit house brand aluminum are reasonable. IMO though for a build up to 300-325+ hp.. Vortecs are the way to go for the $ they are hard to beat and flow as good as a lot of aftermarket heads.

Fast355

iTrader: (2)

Until their wafer thin decks crack the first time you mildly overheat the thing. Even something like an out of the box Assault racing head is a drastic improvement over a factory vortec. I have witnessed cracking in multiple locations, dropped valve seats, valve guides off center, guides that are too tight on clearance and pulled rocker studs on stock Vortec engines. The Hecho en Mexico 062s also do not even reach 220 cfm of intake flow.

dmccain

iTrader: (2)

So now the best factory head GM ever put on a Gen 1 SBC is crap since you got some knockoff Chinese aluminum heads.. I wont argue with you Fast I'm sure you are gearing up to tell me how they done on a swap in a G20 van. Dang that van has had 100 different engines and combos in it Lol

Richardman1992

your head would spin if you heard the stories he told on performancetrucks about his titan and infinity.

Fast355

iTrader: (2)

Really not my point at all, but the Vortec heads are not worth putting a lot of time or effort in this time and age. The Vortec head was the best factory flowing cylinder head and had the best chamber design, but it lacked in other areas compared to some GM offerings. Pressed in studs, valve springs, thin castings, etc.

All I am saying is you can get a lot more out of an aftermarket casting and have better reliability at the same time. The Chinese are turning out some very nice castings now.

The Assaults are actually on my Express van. In the last 8 years it is actually the 2nd set of aluminum heads I have had on it. The Edelbrock Etec 170s were also very nice and I still have those heads on a 305.

Those Chinese knock off heads are making ~500 hp out of a 80K mile factory L31 350 bottom end with a small 215/224@ .050 cam (Degreed out at 218/228 @ .050 with 1.7 rockers) and flow better than many LS factory offerings. After LLoyd ported them those Chinese 23* heads flow as well as a set of ported Cathedral port LS heads.

BEFORE
LIFT------INTAKE-----EXHAUST
.200----------135-------103
.300----------183-------131
.400----------225-------150
.500----------244-------164
.600----------241-------175
.700----------241-------177

AFTER
LIFT------INTAKE-----EXHAUST
.200----------138-------107
.300----------192-------138
.400----------241-------164
.500----------274-------183
.600----------291-------193
.700----------295-------199

Grandview IROC Z

Thank you all for your responses. In particular, I do not know the aluminum heads manufacturer other than Blueprint engines supplies them on their 383.. My major concern is I want a 100, 000 mile engine but yet an engine that can take an occasional autocross run.

tater

iTrader: (10)

Beware of the "stock" Vortec heads lift limit. It's only around .470ish. There are many ways around it though.