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77OMEGA
03-02-2006, 01:49 AM
I think I read somewhere that you can use Mark IV heads on a Gen VI block. I have found some, with casting number 346236. I just want to make sure they will work with my Gen VI block.
Any help is appreciated.
Thanks,
Kirk
Carnivalride
03-02-2006, 04:19 AM
I think I read somewhere that you can use Mark IV heads on a Gen VI block. I have found some, with casting number 346236. I just want to make sure they will work with my Gen VI block.
Any help is appreciated.
Thanks,
Kirk
If I remember right those 236 castings are peanut port ovals, that's for low rpm stuff and small displacement are you sure those are the best choice for your application?
Just my .02 :)
fc-pilot
03-02-2006, 09:02 AM
From what I could find it looks like those are the small intake ports. The real question is what are you looking for out of the engine? With those heads there would not be much as far as high RPM's go. They will fit on your gen 6 block though if you still decide to use them. Do some research to make sure you use the correct head gasket with it.
Paul
Infomaniac
03-02-2006, 09:24 AM
Yes they will work.
victorfb
03-02-2006, 11:43 AM
those are not the "peanut port" heads, but the earlier oval port. you can run them on the gen5/6 with the proper head gasket, but its still not 100% safe. many have done it with success.
fc-pilot
03-02-2006, 01:58 PM
My understanding was that mark 4 heads won't work on gen 5 blocks as well as gen 5 heads not working on mark 4 blocks. Now gen 6 blocks can work with either series of heads (as long as the proper head gaskets are used). At least that is what I have found with the stuff that I have built.
Paul
Carnivalride
03-03-2006, 04:21 AM
those are not the "peanut port" heads, but the earlier oval port. you can run them on the gen5/6 with the proper head gasket, but its still not 100% safe. many have done it with success.
They're not?
346236.....75-87...oval...OPEN...454, 120cc chamber, 225/116cc ports
225cc intake runners are certainly not the normal 255cc intake runner like on a 781 or 049.
Just my .02
Fired Up
03-03-2006, 07:34 AM
I have a set of 049's if you are interested..
Nucking futs
03-03-2006, 07:40 AM
I have a set of gen 6 heads, ported with bigger valves 2.19/1.88 10 * locks new springs set up for a .600 lift roller fresh ready to run for $600.
the gen 6 and gen 5 blocks are the same except for the timing covers.
mk 4 heads will work on either one , just make sure you have enough meat on the head gasket to seal it on the upper side of the head.you will have to modify the gasket a bit , but they will work.
victorfb
03-03-2006, 01:53 PM
They're not?
346236.....75-87...oval...OPEN...454, 120cc chamber, 225/116cc ports
225cc intake runners are certainly not the normal 255cc intake runner like on a 781 or 049.
Just my .02
the small oval port heads (also known as peanut port) were used from 85-96. they hold only 200cc volume. the larger "oval port" heads averaged a 230cc volume. (some 225cc). the 781 and 049 heads are also large ovals but use a slightly larger valve.