What vortec cylinder heads will fit on 78 sbc block? thanks

 

To the best of my knowledge there are only two factory production vortec head castings the 062 and the 901 Ive run into alot of people that think the heads they have are vortec because of the center bolt valve covers but a good sign the heads are vortec is the three triangles cast in the front of the head. The castings are basically the same except the 901 had a specially hardened exhaust seat there was a rumer out there that the 901 casting didnt flow as well but I think that has been debunked. The vortec head will fit your engine but you need to use a vortec specific manifold. downside to the vortec is that they are lift limited .440 to .460 you must measure, the spring seat is smallish and the valve guid is large meaning no dual spring both are easly overcome by the machine shop or other means. I run them and like them.

 

i found you some heads for a small block chevy, doesn't matter on what year it is, just as long as their made for a small block chevy, but obviosly not heads that say that they are for like ls1 and stuff like that, but i'm sure you know the difference. i found some on jegs, the part numbers are 809-12464298 for the fully assembled ones, and 809-12497186 for the bare head. i'm not sure if you are going to read this in your other post in the 2nd generation section, but heres the heads that should fit your block.

 

So are the factory vortec heads different then the ones they sell on Jegs? Also, is there any way around the max lift one them? I have a 355 that has a .480 cam lift in it and I have a set of vortec heads off of a 97 truck, they are the ones with the hardend seats. I wanted to use these heads and build a 383, do you think this will work or what will I have to do with the heads?
Thanks!!!!

 

Some of the aftermarket vortec have the valve seats enlarged and the guides milled down for clearance Ill have to look when I get the chance. The heads you have will work great on a 383 I am starting to think of a winter project along those lines. For clearance you have a few options the backwoods method is to disassemble the heads and grind additional clearance off the backs of the retainers it not really a reccommended way to go but is the cheapest. remember you need at least .060 clearance over thetotal lift. I put checking sping in mine put a dial indicator on the valve stem and measured the distance untill the retainer hit the valve seal I got around .520 minus the .060 and you get a safe lift capacity of .460 stock. I ground off .010 off the retainer bottoms for my .470 lift cam and assembled with manley stock car springs. You will need to measure your heads and see what you have and go from there do not grind the retainersin to the keepers and I suggest running anti pump lifters, the measurements need to be done with the rockers you are using. I was told by crane not to use the self aligning rockers with a solid cam fyi, The better method is to have the machine shop mill down the retainers and widen the spring seat or you can do it yourself comp makes tools for you to do it yourself. A few things to remember about going for big lift with these heads 1) they have pressed in studs the more lift the higher spring pressure the more stress on the studs. 2) if you look at the flow specs for thes heads ther kind of peak around .500 lift. 3) if you look toward porting them as a dyi project leave the chamber alone and the intake port alonetouch up the exhaust side.