[f/bird]

Any pontiac guys with tips on upgrades for 350's (pontiac) 70's

[g&s restorod]

depends on how much work you want to do/spend, cam kit heads headers intake best bang for buck. find a set of 6X-4 heads and buy a kit with cam springs retainers roller rockers etc. get the heads done and install everything with a good 1800-6000 rpm intake 600cfm double feed holly and headers, you will be surprised how snarfy it is! I have done this on around eight 350s and they all could hang with the 383 strokers no problem!

[f/bird]

What I have is a 76 f/bird with 6x4 heads w/2brl. 3.08 pos. auto. I have collected a E/B performer intake ,4brl qjet,and I have a new 5oooo volt dist. for it also .My plan is to add a cam kit of some sort (don't know what is the best one yet) I hope I can leave the heads on . I have true dual ex . w/flo/masters . It sounds meaner than it is !!!LOL! Any tips are appreciated !!

[LATECH]

Sounds like a good candidate for a comp cams XE 256 cam.
The 6X-4 heads have 91 CC chambers and compression will be kinda low.
the comp cams XE version "builds compression" so it should liven the 350 up.
I wouldnt get too nuts with a 350 as far as spending money, but you do have a lot going for it as it is. All I can see is that it needs a cam. You could also mill the heads and boost the compression ratio.There is plenty of room to go up on the compression before you need to raise the required octane up from 87.

[cobalt327]

Jack up those heads and slide a 455 under them!

[f/bird]

I WISH !!! That's for a later date . I just bought this a year ago and I've already put a ton into it and I'm waiting now to get it back from paint . So I just want to drive it for awhile for now .

[g&s restorod]

above mentioned cam is about right, mill the heads and get some roller rockers

[Mr. P-Body]

Agreed, XE256H is a good street cam for the little Pontiac. However, completely DISAGREE that 6X heads (of any description) are "good" for performance on a 350 (about 7.8:1 static compression). A 72-74 CC head will give the desired 9-ish:1 ratio (9.14 using common gasket and deck clearance stats). IMO, the best heads for 350 are the 47s ('69 350"HO"). 350s "like" small valve heads "better" than large valves due to the small bore size. I know... Pontiac put 48s on 350s (large valve), true enough. I still "like' the 47s better. The added flow of the large valves isn't necessary for the smaller displacement (Pontiac heads were designed to "feed" bigger engines than this). A 350P can be a snappy, "torquey" street engine.

Performer will provide MAYBE a little gain in performance over the factory 4-bbl. intake. The weight "savings" is the biggest advantage. Pontiac manifolds flow very well compared to other "stock" intakes, particularly when Q-Jet is used.

When "going to the next level", forget about a 455. 400 blocks are both stronger and MUCH easier to "come by". Using a "stroker kit", it's quite easy to make 500-plus HP and over 550 lbs.. of torque with iron d-ports and proper preparation. Get Jim Hand's "How to Build Max-performance Pontiac V8s" published by SA Designs. Excellent info in there. Some of it is out-dated now, as the book was published in '04. There's a "re-write" in the works, but many of the original contributors have not been involved. It appears to be a re-hash of the old book without modern "race" info included. The days of building a Pontiac to be "all done" by 5,200 are over. Some of the die-hards can't accept that. We routinely build 461s that peak power above 6,000. 10 second, 3,700 lb. Firebirds and GTOs abound, in "street trim". We've come a long way... (:- And the aftermarket has "stepped up" with lots of GREAT performance parts.

Jim

[f/bird]

I maybe able to find a set of 47's as I've seen them on craigs list a few times . The perf/qjet are what I have collected so far and I'm just rounding up parts I'll need to do this project and want to doit as close to right that I can !! Do the 47's have to be 69 ? I do know of a set of 62's but I'm not sure he'll part w/them . If I use the 47's what's the best cam to use at that point? And do I need to have screw in studs or these heads have them? Thanks for all the advice !! I want to drive the 350 for awhile if I can without sinking alot of $$$'s in it and save up for a 400 . If I get enough h.p. out of the 350 I may be happy w/that as I'm not going to the track w/it but I mwant it to be a little snappy and fun !

[g&s restorod]

go with the 6xs then later when u upgrade to a 400-455 you wont be paying for another head job or just get some 16 heads

[Mr. P-Body]

47s ARE '69 heads.

16s ('68) and 62s ('69) are "large valve" heads.

XE256H is still an excellent grind for the little Poncho.

Jim

[cobalt327]

Originally Posted by f/bird

I maybe able to find a set of 47's as I've seen them on craigs list a few times . The perf/qjet are what I have collected so far and I'm just rounding up parts I'll need to do this project and want to doit as close to right that I can !! Do the 47's have to be 69 ? I do know of a set of 62's but I'm not sure he'll part w/them . If I use the 47's what's the best cam to use at that point? And do I need to have screw in studs or these heads have them? Thanks for all the advice !! I want to drive the 350 for awhile if I can without sinking alot of $$$'s in it and save up for a 400 . If I get enough h.p. out of the 350 I may be happy w/that as I'm not going to the track w/it but I mwant it to be a little snappy and fun !

Yeah, forget about building a piss poor weak 55 when you can buy a 400 and then go buy a brand new rotator plus different heads, etc for it.

That car will go effortless 12s w/nothing more than a cam, headers, and a 55 short block under those 6x-4's. Never need to rev it past 5000 rpm. Same gear ratio even.

If you want to build the 350 that's fine. Changing the rear gear ratio will be a big help. If you want to go w/a 400 and not stroke it, that's another decent option. But unless you plan on hammering on this I wouldn't necessarily just jump into a 400/455. It has its place, but that's not under every Pontiac hood.

[LATECH]

Originally Posted by f/bird

I maybe able to find a set of 47's as I've seen them on craigs list a few times . The perf/qjet are what I have collected so far and I'm just rounding up parts I'll need to do this project and want to doit as close to right that I can !! Do the 47's have to be 69 ? I do know of a set of 62's but I'm not sure he'll part w/them . If I use the 47's what's the best cam to use at that point? And do I need to have screw in studs or these heads have them? Thanks for all the advice !! I want to drive the 350 for awhile if I can without sinking alot of $$$'s in it and save up for a 400 . If I get enough h.p. out of the 350 I may be happy w/that as I'm not going to the track w/it but I mwant it to be a little snappy and fun !

Dont put your faith in the Head charts stating the chamber size. Although many are correct there are a lot of charts , including wallace , that are wrong on some head volume sizes. Trust me on how I know.
I bought a 73 350 engine,as a spare, has 46-4 heads ,they are 96 CC as wallace said. I know for SURE cause I CC ed THEM MYSELF. They would be good candidates for a 455 build.
However, i also bought a set of 7H1 heads as they were supposed to be 80 CC chamberes, They came in at 91 CC. Thats a ways off you know.
Also some heads due to age have been milled, so they will be smaller in chamber size than what is listed. Best bet is to shop for heads by number, then before buying CC them to be sure of what you are getting. Or you will end up with 5 or 6 sets of heads ...like me.
I had the 7H1 heads milled .045 , I CCed them .they are 82 CC now.Perfect for my build , with zero deck and .041 head gasket my static is 9.4 to 1. They will be going on a 389 block punched to 4.120 (400 CI)

[WDCreech]

Also for everyones information, If milling a Pontiac head more than .015 or .020, mill the intake side an equal amount so that any intake manifold will fit correctly without milling.

Bill

[LATECH]

Originally Posted by WDCreech

Also for everyones information, If milling a Pontiac head more than .015 or .020, mill the intake side an equal amount so that any intake manifold will fit correctly without milling.

Bill

Thanks for the reminder Bill. Thats good lookin out.
I did that with my heads as they were milled .045. Just forgot to mention.