ultimatefighter

I am having a brain meltdown , so i will ask some pros. I am building a 350 TPI or HSR setup. Can any head of my choice work? Or do i have to stick with a certain style? I am looking at Patriot or AFR's. Thanks.

InfernalVortex

iTrader: (4)

1. Before 86 there is a different style of bolt pattern.
2. Newer Vortec heads have a different intake port pattern (different manifolds required)
3. Just make sure the chamber size is right for what you want and the compression shouold be fine. For a 350, it's usually 64cc. Bigger chambers mean less compression and less power. Think 400 ci 70's Trans Ams that couldnt break 200 hp
4. Im no expert on this, but really old heads I think dont have hardened valve seats for unleaded gas and they may not have the holes for installing A/C and other accessories... but Im not too sure.

Heads are complicated, Im in the market for some myself and Im just trying to learn as much as I can. But stock chamber size is 64cc which is important if you want to run streetable compression with flat top pistons.

Of course, I could be wrong, Im no expert, but I figure you may benefit from what Ive been able to gather in all my research.

84z28350

55-86 and 87+ were the years for the different centre intake bolt angles. Not a big deal, intakes can be modified or purchased to fit either one...

Vortecs are a whole different ballpark, definately requires use of a vortec intake.

And yes, the real oldschool heads do NOT have hardened valve seats and will definately fail if they are not upgraded (if they havent been run on unleaded and failed already) and same with the accy's bolt holes, probably have to drill and tap them yourself. But it doesnt look like you plan on using some old junk hads anyways...


So anyways... First things first...

Which intake are you going to run? Do you have one already or is that yet to be purchased?


AFR's are definately a nice piece, but they are also worth a good buck and dont be surprised if your on a 4month waiting list! they are also a bit overkill for a mild street motor, you may be better off finding some cheaper heads.

What exactly is the goal for this motor?

ultimatefighter

I am getting a 350 roller motor. Replacing the 305 in my Z28 1992. I just didn't know if i could just use my TPI with some aftermarket heads until i can afford the HSR. And then i don't know if all that interchanges? My goal is around 350-400 horse. Hot street, so i am not looking for topend necessarily. I know the TPI will choke out whatever i do, but can i use it until i get the HSR? Thanks

l_dis_travlr

The biggest headache will be the intake bolt pattern.
If your TPI has the canted center set bolts, very
few aftermarket heads are compatible with this.
But if the long-range intent is to replace the TPI,
than a short range solution might be to mod the
current manifold to fit the more readily available
heads. Patriot is offering a new head that's
getting pretty good reviews, for an excellent price.
Good luck, hope this all helps.

ultimatefighter

Ok, i have decided on the Patriot super pro series 195cc heads. But, i went to summitt to look at the HOlley Stealth Ram, it says it fits applications up to 1986. What is all that about? Also, what injectors would i run with the HSR? Thanks

l_dis_travlr

This link has some discussion about the HSR & Patriot
heads you might find useful. If not, the participants
seem like the usual good-guys-ready-to-help-other-
genuine-gearheads (i.e. low tolerance for smart-alecks
& gas-bags). Good luck.

https://www.thirdgen.org/forums/afte...ies-heads.html

ultimatefighter

Thanks for the link.

84z28350

The one that they list for 55-86 does not have the center bolt holes on the manifold angled to match the 87+ style heads.

Which means it will not readily drop into a stock roller motor without modifications but what it WILL do is work perfectly on a set of aftermarket heads! (granted you done get vortec style heads)

JTB91RS

Don't mean to hijack the thread, but I am having the same questions at the moment for a similar situation, and I just wanted to get some clarification. The only difference between pre '86 and '87+ heads is that the '87+ heads have canted or angled center intake manifold bolts? Also, if I already have a pre '86 TPI setup and an '87+ engine, is it a better idea to replace the heads to pre '86, or get a new manifold?

Thanks,

John

l_dis_travlr

There are internal differences. You don't mention what
the 87+ engine is. The TBI versions of both 305 & 350
usually had the "swirl-port" heads. There is a hi-perf
TPI 350 version (L-98, casting number 1014083) that
is a very good performer. There is a wealth of more
detailed info elsewhere on the board.

Which is a better idea? Depends on what you have,
and what you're trying to accomplish. I don't have
any actual experience with TPI units, but if all the
other parts interchange, the path of least resistance
might be to e-bay just the manifold. Also check the
parts for sale & parts wanted sections here.

Good luck,
kk