Aftermarket big block heads
 

Im considering buying some new heads and i want to know if i should trust aftermarket heads out of the box.

Edelbrock makes the cheapest marine grade heads (that ive seen) and i have seen some dynos with good power with them, but ive read that they must be checked before bolting on. Now my first choice is dart iron eagle 308's but they are not cheap, but im wondering if the price will sort of even out if i go with dart over the edelbrock heads because of the machine work the edelbrocks 'will' need.

Im assuming that the dart heads can be trusted out of the box.. but maybe that is a bad idea too, i would love to get my short block back from the shop and have some heads waiting to bolt on brand new... is that wishful thinking?

I used hears from RHS with zero issues.

If I were doing it I'd go with Dart, RHS or AFR. I used Dart on a recent project and they work great.

I have used edelbrocks and they are nice. The one good thing is the 110cc bumps the compression. I have also used Dart and AFR. Depends on how deep your pockets are. AFR has some sweet OVALS heads. Get ahold of RMBUILDER you will give you a good deal.

I would never think of running a set of heads out fo the box.
You need to check the valve guides clearance. You also need to setup the springs for the cam you are running.

So general consensus is that i need to get them checked regardless of manufacturer... In that case it is probably better for me to just go with the edelbrock aluminum marine heads and a matched cam spring kit, the edelbrocks come with no springs.

fixx
 

that's the way i went,,just make sure you dont use cheap springs..isky tool room springs are the ticket..

They all make a decent product , but I would not use any of them right out of the box . This is not a place to cheap out you can make some real HP gains with the proper head's . Take the time to do your home work it will pay off in the end for you . I would also look at brodix . PS If you don't like the price of the iron eagle's you REALLY won't like the price of the rest of them ! just saying :eekdrop:

Yea from what ive heard the edelbrocks really dont flow all that much better than gm rect ports, but they are brand new come with stainless and inconel valves and can be ported for more gains... i dunno. Right now its between the edelbrocks and the darts. Probably going to come down to what pistons are in my shortblock waiting to hear back from the machine shop, because the edelbrocks come with 110cc chambers which will bump compression

If i end up having to bore and get new pistons i will go all out and get the darts

FYI The Edelbrocks do need some port work out of the box. That is why they are less than the darts. Also make note of the fact that these are identical to the heads on a 525 Merc motor. That means evrything will bolt right up in the right places. I bought the Edelbrocks becasue I did not like the fact gthat on the Darts, the exhaust side of the head is angled differently and since I have twins I did not want to deal with my exhaust not lining up.

Smitty

The Edelbrocks are a decent head but the guides are usually too tight and by the time you set them up with springs, locks, retainers, etc. They're not a great deal. Get a hold of RMbuilder on here, Marine Kinetics. He can set you up with a pair of AFR's with the right springs and valves that you can absolutely bolt on right out of the box. They will make more power then the Eddy's too.

Are the exhaust ports raised on the AFRs? My Etops are grazing the hatch already!

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.

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.

Pay now or pay later , but you will pay !!!!!!!! :party-smiley-004: just saying

Buy them once buy them right. If you need to buy heads or refurb some heads buy a set of aluminum Dart's or AFR's now. You will kick yourself later if you don't.

whats wrong with Brodix? i see only one guy that recomended them

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.

Great post , exactly the kind of info i crave . Thanks

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!

If you already have all the answers :rolleyes: why ask the questions

If you can wait a couple months I will have some low hour gm rectangle port heads for sale, switching to afr's:evilb:

I liked my old 188's also. If I find my seat I can sell them to you. Yes they were just freshened up. At the least pay to have them Magnafluxed. Cracked between the the valves. I Have new heads now.

I went with a set of ARF 290 Ovals fully CNC Port Work. Super sweet heads, Spend the extra cash. Bob at MK gave me a great deal!!

290 ARF Heads

Do you think what I'm saying makes sense? I mean from a simply money standpoint not worrying about every last ounce of hp what I'm seeing is that aftermarket heads are going to cost me about 1000-1500 more than rebuilding Gm rect ports. I'm learning as I go here this is my first big block.

Heads play a big part in how much power you'll make. I decided on the AFR 305 with hard coat for salt water use. I purchased them bare and had tthem built. Short block was a 509. Nothing crazy. Those heads flowed awesome 610hp with all accessories ( - water pump) and eddie marine manifolds.

Worth every penny IMO

+10 on the AFR's. I have had or seen the seats fall out of countless GM heads even after fresh seats have been installed. If your bent on iron get some Dart's. I do have several sets of GM iron rec port heads, 2 pair with missing seats otherwisw very nice flow numbers and 1 set in perfect condition. All have big valves, inconel ex, and have been ported by Spyder Performance that are for sale cheap.

Im also doing new power at the end of the season, 502's now torn between 509's or 540's with aluminum heads, great thread.

Its a shame you have to put all this high dollar stuff where no one can see it

How much $ are a set of AFRs??

3000-4000k depends on how you dress them, more moving parts in the heads. Why go cheap there, help the engine work easier. Good flowing heads make ez power.