Tore my 502 motors down today and found cylinder wall damage from rust ( I had a reversion problem with Gil exhaust with very short risers for silent choose ) I have already purchased CMI sport tubes and was just going to freshen up the heads when I found the problem so I decided that it is time to make more HP. My plan is to bore the engine to a 509 use Eagle .250 longer rods with the SRP 10.1 to pistons and I would like to run my present cam that is a custom grind Crane Hyd roller intake at .050 is 232 and lift is 598 the Exhaust is 244 with 632 lift Cranes part # given to the cam is HR-232/352-2S-12 IG but if there is a better cam that I can buy off the self I would would not hesitate to change. My goal is for 650HP I will be using C&S 980 CFM Aerosol Billet carbs, Crane ignition systems, Magna flow 280 fuel system, My biggest question is what head and intake comb to go with.I am going to run wet exhaust. Thanks Brian

come on guys I know I am not a well known name here but have been lurking for years

Brian,the best way to take your motors from 435/450 gross hp to 600 plus is to buy a set of afr cnc 315 heads. They are not cheap BUT they flow about 25% better than stock rectangle ports. Most heads out there,even the aluminum ones and bigger port darts,brodix etc don't have the kinda flow the afrs have. Rm builder/bob madera-585-654-8583 is a dealer for them and can give you pricing as good as you'll be able to get from any jober or even better.As far as a cam,he custom profiles and specs billet hyd rollers for the same price you will pay from jegs or summit and his combinations work very well. When I built my 540 blower motor he supplied my custom ground cam,he told me I should see 950 hp at 5600,it would idle at 700 rpms and should pull 10-11 inches of vacuum at idle. Well,he was so close I was amazed,it made 944 hp and idles exactly where he said it would,If I really used my connections I mighta saved 50$ on the cam for a off the shelf grind but it would have been a guess at what would work. Feel free to call him,you won't regret it,Smitty

Smitty I thought you were the one that had reversion with wet exhaust and AFR heads. My worry with them is that we get a lot of seaweed around here and always risk over heating not only that have had problems with intake and exhaust threads with aluminum heads in the past. Good thing is money is not a problem at this time just pulled $80,000.00 out of the house to build deck and work on pool room but that can wait.
Did you get your blower together yet and how is the box working out. Brian

Brian,I had reversion with my lightning headers,went to stainless marine hi tq 3's with water added in last few inches of the tails and its fine but I'm not sure with cmi sport tubes what will happen. I do know that wags 382 is running the afr 305's with cnc'd chambers on his hp 500 502's with whatever manifolds they come with without a issue. I installed the ext box in the plus 1" position in june and had boat back on the water for 4th of july weekend,the following saturday my procharger wiped out and I bought a used one from Cigdaze and had it running by the next weekend for the boynethunder poker run. The box didn't produce any gains at all for my boat (actually lost 2-3 mph)and it now porpoises constantly from 2800-4000 rpm's unless I dig the tabs in real hard,it drives terrible in rough water and cavitates when you hit 3000 rpm's so it was a bad idea for my boat but the only way to find out was to buy one and put it on. Today I rebuilt my lower drive (heat treated gears just started failing) and installed a 1" drive spacer to see if boat will at least get back to where it used to be. I had to have drive spacer custom machined because the max worx tower base wouldn't fit into the spacer. I might test it this evening but I drank a little (alot) too much last night and don't feel 100% today. As far as thread problems with the afr heads I think they have steel thread inserts in the manifold holes,haven't had any problems with mine. It will be hard for you to break 550 hp let alone 600 hp if you stick with iron heads and 510 ci unless you have some real serious professional porting done to them. My merlin vr's flowed something like 310 intake/215 exhaust compared to 385/300 plus for my afrs with same size runners,Smitty

I will call Bob on monday and most likely order 2 sets what about intakes.
Sorry to here about all your bad luck but at least your out drinkin. Thanks Brian

I'm not sure what is the best intake,I wold ask bob madera what he likes or contact scott at cfm,Smitty