Aftermarket big block heads
#12
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Joined: Oct 2010
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From: Cheboygan, MI
Definitely go with the AFR's the 305's with CNC'd chambers are the best bang for the buck. Although the exhaust ports are raised .250. If your getting new pistons, what do you care about the chamber size, just order the piston with the correct dome. Check with RMBuilder, have him match up a cam while your at it, you'll be happy you did. I just rebuilt my motor and I already had a pretty big cam so I didn't upgrade, wish I did now and the motor is in the boat. Now I have to cut a hole to change the cam, would have been much easier with the motor out.
#13
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Just heard back from the machine shop, dont have to bore, all pistons good. 118 cc chambers end up with about 9.25 compression with the pistons in it. The edelbrocks are going to end up about 2400 bucks said and done with what the machine shop said they would want to do. Might try to find something cheaper, if i could just find a good set of gm rect ports.
#17
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From: Cheboygan, MI
Do the research and check out the article from Chevy High Performance. They did a side by side with all the major players in cylinder heads. The small 305/315 AFR's outflow and out performed every other head tested in every aspect, average torque/hp and peak torque/hp. If your buying heads to gain power it only makes sense to buy the heads that will make the most power per dollar. I just rebuilt my engine last year and I'm an Engineer and I poured over every article, dyno report, data sheet I could find to make sure I was making the most power for every hard earned dollar I was spending. I could have bought other heads cheaper, some a lot cheaper. Bob Madera is one of the most respected people on OSO and he recommends and sells AFR, that has some real weight. My engine builder told me his experiences with all the brands I was considering and it made the decision easy. I'm happy now that I bought the AFR 305's with the CNC'd chambers, they actually do the bowls also. I did the gasket match and port touch ups myself. I now have a Velocity 280 with a 524ci BBC that is running real close to 90 and I still have a lot of prop tuning to do. In case you think port velocity isn't all that important, I just ran 30 miles to Mackinaw City and back and got 3mpg at 60mph and like I said I still have a lot of tuning to do. I have a 90ph boat that gets better fuel economy than my brother in-laws 4cyl Bayliner. I can go over 200 miles on a single 80 gallon tank of gas. Over the next few seasons I will save in gas what I paid for those heads, think of it as putting money in the bank.
#18
Do the research and check out the article from Chevy High Performance. They did a side by side with all the major players in cylinder heads. The small 305/315 AFR's outflow and out performed every other head tested in every aspect, average torque/hp and peak torque/hp. If your buying heads to gain power it only makes sense to buy the heads that will make the most power per dollar. I just rebuilt my engine last year and I'm an Engineer and I poured over every article, dyno report, data sheet I could find to make sure I was making the most power for every hard earned dollar I was spending. I could have bought other heads cheaper, some a lot cheaper. Bob Madera is one of the most respected people on OSO and he recommends and sells AFR, that has some real weight. My engine builder told me his experiences with all the brands I was considering and it made the decision easy. I'm happy now that I bought the AFR 305's with the CNC'd chambers, they actually do the bowls also. I did the gasket match and port touch ups myself. I now have a Velocity 280 with a 524ci BBC that is running real close to 90 and I still have a lot of prop tuning to do. In case you think port velocity isn't all that important, I just ran 30 miles to Mackinaw City and back and got 3mpg at 60mph and like I said I still have a lot of tuning to do. I have a 90ph boat that gets better fuel economy than my brother in-laws 4cyl Bayliner. I can go over 200 miles on a single 80 gallon tank of gas. Over the next few seasons I will save in gas what I paid for those heads, think of it as putting money in the bank.
#19
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This is awesome info, but cnc afr's are simply out of my price range theres no way around that. Im most likely going to be rebuilding some freshwater 188 heads, yeah it wont be cheap but it will still be cheaper than buying any aftermarket heads and the money saved will be going into my freshwater cooling system. Power is not of utmost importance to me, it is important for me to be over 400 horse and have a chance at hitting 70, but besides that reliablity is the name of the game for me, and spending 2-3k on heads isnt going to improve my reliability, i have the money to do it but it is a waste as far as im concerned in my 1979 24 foot boat.
I guess after reading through all these threads i get caught up when people say stuff like 'it ends up costing near the same to rebuild heads' when honestly it doesnt, its going to be about 1000 bucks more for me to run the edelbrocks after the machine work and hardware they will need and they are the cheapest marine head out there!
I guess after reading through all these threads i get caught up when people say stuff like 'it ends up costing near the same to rebuild heads' when honestly it doesnt, its going to be about 1000 bucks more for me to run the edelbrocks after the machine work and hardware they will need and they are the cheapest marine head out there!
Last edited by sparky24; 07-19-2012 at 05:41 PM.




just saying



why ask the questions