455 Performance upgrades with NO headers

I did a quick search and found this thread:

https://www.v8buick.com/index.php?threads/anyone-port-cast-exhaust-manifolds.375495/

The OP asked about porting 350 manifolds, but the conversation eventually turns to 455.

 

Thnx alot so gain per$ , it's not worth it to port them, UNLESS it's absolutely a must to " look" stock , with manifolds.

So I a. Wondering if a
Heads ( fully ported and polished + stage 1 valves and springs)
+ cam
Will be a good idea if I can't get her to breathe really, or is it a waste of $$$.

 

I'd think for what your doing, a good performance valve job and bowl cleanup will get you where you need to be for a reasonable amount of money. Then work closely with your machinist to blue print the crap out of the build. You'll need to know and understand: deck height, piston dish, quench area, DCR, ring gaps, bearing clearance and cam timing. This is where you're gonna find your power.

 

ya know id have to look but i think a set of big car headers would clear in a c10. i know when i bought a aluminum radiator for my other 72 it shared the same as a 67-72 c10. so the fullsize cars do share some parts with the fullsize trucks.

 

For a full size truck, the frame rails are really close together in that vintage of C/10, something like 21 inches between them. They do widen out to about 27 inches at the very back of the engine compartment. Buick 455 is quite a wide motor, plus you have the exhaust ports angling down, which aims them right at the frame rails. Pretty sure not even shorties are going to work. I spent a considerable amount of time measuring and trying to come up with a way to make headers work with my C/10 and 455 combo, but eventually just went with manifolds, and they fit very nicely. I am using a 1967 drivers side, which is said to be 5-7 hp better than the 68-76 manifold. I did "port" them, which actually is just opening up the exits. 2.2 inches is about as big as you dare go and expect them to live-might get away with 2.25". I had a 76 driver's side that I opened up to 2.3" and it failed in a few months. Stock outlet inside diameter is 2 inches. I would like to have Jim Rodgers do a set. He welds different, bigger outlets on.

 

I Have a local source
whos well known in the porting business he does the heads for Caddishop, he ports the 427/500 iron heads for them
and hes LT1 and LS guru... guy knows his stuff... i trust him
http://elliottsportworks.com/
I spoke to him he could also port my ex. Manifolds 2-3 inches into the manifolds... he would open up the Exit and port match.

all in all for a reasonable price.

What would you guys recommend in terms of milling the heads and possibly decking the block when using Stock 72 pistons ?

i have a S divider intake on the motor now and could think about port matching that as well to gian more flow + adding a 1ni spacer ( i know the s-divider is not the best choice but it is what i have..

PS: does TA have there cams in stock ? any body knows? i guess i can call them

 

Honestly I think it'd be more effective to get replacement pistons rather than try to work with the big dish stockers. The TA 1621 A's have the right pin height to keep machining to a minimum, and in their catalogue they have a handy chart to understand what it takes to get to a specified compression ratio out of them. Thats said, if you really want to use the stockers, you can artificially crutch the DCR using cam timing and still make good power on 8.5 compression- I made it into the 12's that way. Read up on DCR and download the calculator, Larry has plenty of informative threads discussing this.

 

Ported iron stage 1 heads, 10.5 to 1, sp1 intake, TA284-94f solid, roller rockers , headers
364 rwhp and 506ftlbs rwtq
On a 230 shot of nos
547 rwhp 766ft lbs rwtq
If you want to run nitrous on your stock motor run some cometic mls head gaskets and get an adjustable oil pressure regulator, don’t over rev it

 

Can’t go wrong with one of TSP 9.5 inch converters. I running stock low compression 72 - 455 with stock small valve heads, through exhaust manifolds. To date best pass was 13.84……I believe the convertor is a huge part of moving this full weight air conditioned GS.