I have a few questions, (first post) I have a block 1978 350 30 over power pro flat top hypernumatic Pistons mild cam.. I took my heads off because I Believe they may be warped. My questions are, I traded some parts for some vortec heads off a 98 z71. Should I be concerned they don't have kidney (or heart) shaped ports on bottom? Also which springs for Cam? I also came into a Howard's cam for 2800-6600 rpm (not what I'm looming for) but that is an option I think I want to keep my cam, use vortec heads and get a performer rpm airgap or equivalent intake. Fyi I am running msd atomic efi

 

What is the casting # of the heads?

If they're ACTUALLY Vortec heads, which a 98 350 shold have had (Z71 doesn't matter... it's just a buzzword, the actual package is only the skid plates, upgraded shocks, and GINORMOUS STICKERZZZZZZZ!!!!! it has nothing whatsoever to do with the engine in any manner way shape form or fashion) then they'll bolt right up.

Main thing you will ABSOLUTELY need to do, is replace the valve springs. The stock truck springs are inadequate for the little weenie cam-shaped thing those motors come with, let alone ANY aftermarket one.

As far as what springs to use, that depends ENTIRELY on what cam you have, and how much risk you're willing to take. But for a streetable motor we can make a fairly good guess. Springs that will work with just about any cam you can realistically run on the street, without machine work, easily enough: http://www.texas-speed.com/p-1383-ls...od-to-550.aspx; the Comp retainers for LSx springs and SBC valves, 787 I think is the #; positive seals; and the keepers that go with those retainers. You'll need to switch to self-aligning rockers no matter what else you do.

 

I'm supposed to pick up the heads today I will post the numbers, I do know that the manifold will be different so I will have to buy a new intake manifold, that's a great price for those Springs, cams sells a kit for like 260 I think it only handles to 470 lift. I wonder if I can reuse my performance Springs and Rockers in my current head, had was put together by Phoenix engines in Arizona I don't know if there's any way possible I can get the part numbers but I will try. When you say using self-aligning rockers if I sent a picture of my existing rockers I wonder if someone would be able to tell if I could use them in the new head

 

Those are yerbasic stock stamped sheet-rubber garbage; but yes, self-aligning. You "could" use them but you "could" jump off of a 10-story building too I suppose... "could" doesn't automatically make it A Good Idea.

 

Lol, I'm considering getting a crate motor and upgrading springs and sticking my cam into the goo. 1 dude never met up with vortec heads. 2 ran straight edge on heads looks pretty good, head gasket looks ok, will pull valves and check for cracks inside, if not possibly block.