Unless you go to a higher compression than you would with the iron heads, the increased heat dissipation of aluminum heads will actually loose power. Apples for apples in a non-performance app, iron would be better. Better flow would negate the loss, but if you were to maintain a lesser compression level, the better-flowing heads in an iron version would make more power than the aluminums would.

Well the truck is a 89 k1500- 6000lbs and a daily driver so the compression ratio would not be as high as on a lighter car. Option 1, iron heads with 9.0-9.5:1. Option 2, 10.0:1 flat tops with aluminum heads, both options with thermally coated valves to promote octane tolerance furthur. Would like the vehicle to be able at least to run OK on 87 octane fuel due to cost and poor fuel economy. Converter on the 700r is stock, with 3.73's. To add to the 7747 ecm is a Perfect Power 7 piggyback ecm with wideband ar trim and switchable octane tunes. Price for the RHS heads $575, Etec $690, I've checked shipping and it would be quite expensive from the USA negating any savings. I understand what you say about theory of the different materials and would agree, except from the testing I have seen- the aluminum wins every time- but who really makes an identicle head in either material. So from a capabilty standpoint are the RHS heads better than the Etecs?

I would go with the RHS heads since you can get them with the bigger 2.02 1.6 valves. Correct me if im wrong but the 170 e-tecs come with 1.94 1.55 valves.

Here are flow numbers for the Pro heads 2.02 1.6 with some bowl work.

100 - 80 / 70
200 - 141 / 130
300 - 188 / 163
400 - 229 / 167
500 - 255 / 173
550 - 265 / 175
600 - 260 / 177

OK so i was looking at my heads again today and the numbers on the passenger side head read 3951598 and the numbers on the drivers side head read 333882. What kind of heads do I have exactly? Can anyone tell me?

flows look decent, a good resource search is 'king vortec' under chevy hi performance- too bad these weren't included.

With the application being a truck and mild performance, I'd probably stick with the smaller valves for increased signal. Dollar for dollar (I'm guessing the prices you listed were each), with the cost for you only being slightly higher for the e-tecs, I'd probably go that route. - 10:1 on 87 octane is do-able with aluminum heads and good tune.

85Firebird350 - 882's - 76cc open chamber bathtubs with low runner height and crappy flow. If you get some decent heads the difference in performance will blow your mind.

The 170 e-tecs are $419.50 each bare through summitracing.
The 2.02 1.6 RHS are $249.98 each 35.00 plus shipping bare on ebay.

Thats close to a $300 price difference.

Yeah I figured a savings of $200 for the pair. Talked to my machinist today and he likes Edelbrock, you know exactly what your getting- a great street head. He has also used the old Protopline lightning model in race engines and has been impressed with the quality of the piece, I compiled all the relevant flows between stock vortec, mild vortec, etec, RHS vortec; he thinks the RHS is worth pursueing- waiting for a price through him now- says the best way to order the heads complete- yank everything off and sell it and put a set of beehive springs and undercut valves in.

For what you're going for I wouldn't spend the $ to swap the valves. Stock vortec valves are pretty good, and for a truck app you won't notice the difference in the under cut. I'm a firm believer in good springs though.

He was thinking of saving wieght where he can on a pushrod engine, not the flow difference- also we were talking about AFRs apparant recall for bad valves.

AFR's recall is on the LSx style metric valves they're using in the new eliminator series heads. - The weight difference is also very minimal, again not noticable on the intended application.

Believe me when I say that he 'Grant' has talked me out of hundreds of dollars- if not more of extra work, that I read about in the various mags. I guess in his experiance he seen some problems with 'stock' valves and springs.

Going ahead with the RHS Vortec's, will order on Monday. Best price is $250 each bare Cdn= +-$210 US$ (no shipping) from a local chain on promotion, talked to their head machinist and he just loves this head, asked about the Etecs (not much said). He has a preference about ordering in all his heads bare (including AFR) because of past quality issues with hardware (or claimed hardware brands) included with the head, I suppose when your a commercial shop why get burned by parts that are easily sourced and installed, I guess every penny saved is profit- RHS claims Comp components. Looking forward to lightly working these over and assembly.

RHS is 100% Comp Cams parts, since Comp now owns RHS(formerly Topline). - I too believe in buying bare heads and installing my own desired components. - I'm sure you'll be happy with your purchase. I wish the set I have at home were mine, but, unfortunately, they're a buddies' which I'm finishing up some port work on.

I would have loved an aluminum version of this head if only for another choice besides AFR and the Etec 200, 2.02/1.6 and higher velicity ports, the wieght savings, and the coolness factor. I was surprised at the wieght of Edelbrocks aluminum TPI lower manifold and runners.

i bought some 215 Dart heads for my 388, they work great but i wish i would of bought the AFR 210 heads. For $400 more i could of bought the AFR

.

You have to draw the line somewhere, I wasn't afraid to spend the money on the AFR, but for my application they simply were not needed- strong 4x4 motor no competition. Better to buy right the first time rather than wish you had after the fact. In this case I feel I made a good choice.