1971 PONTIAC 350 CMASHAFT SELECTION

I am new to this HPP, i also live in australia, i have a 1971 firebird with a 350 poncho, parts are a nightmare to find and shipping even worse, not to mention the AU dollar, i would like some advice in regards to selecting a camshaft, stock camshaft is in engine at the moment, ( matching number engine )

Modifications are as follows

750 vac sec holley
elelbrock performer intake
Custom headers, full dual exhaust
3:42 lsd auburn true trac
th350 stage 2 shift kit with 2500 high stall

now wanting to get into the engine, will start with cam and then heads, due to long shipping time and high cost would like to get to right first time,

i want power to be all down low, thats where it matters to me, any help would be great thanks  

I have a 72 'Bird w/ a 406 due for an overhaul/upgrade, so I'm installing a running 350 I picked up to get my car on the road again. I wasn't thrilled with the 7.5:1 CR or stock cam, so I'm swapping the stock no. 4c's for some no.48's, installing a Crane 272H cam (214 @.050/.454 lift, 110 LC), 1.5 roller rockers and a new oil pump. My short block is good (pulled the main caps- journals are very clean), so I'll button it all back up and get the 350 in the car soon.

I also run a Holley 750 vac sec and e-performer, and Hooker comps w/ 2 1/2" duals. It should run almost as nice as the 406, since the no.48's were on that motor and had a Crane 284H cam.

You can also get a 383 stroker kit from Pacific Performance Racing. Ace has got a killer package for the 350 that will make it a screaming 383 that will make as much torque as a 400 with the right heads.

Geno  

Thanks heaps for your help, you wouldn't happen to know any one with a set of no. 48' s, or a stockist of similar parts, australia are mad for only stocking chev and ford parts, secondhand parts are more rare than hens teeth. that cam was the exact cam i was looking at, 110 lobe sep is perfect to boost comp on the pontiac engines so i hear,  

Good high performance Pontiac heads are hard to come by- I'd try Ebay or Craigslist. The nos. that are good performers are nos. 12, 13, 16, 48, 62, 670- all are D-port heads with 2.11/1.77 valves, screw-in studs, and have 72 cc combustion chambers. These will give you a 9:1 CR with flattops at zero deck.

If you have the stock no.94 heads with 96cc chambers, you're at 7.5:1 CR and you're not going to gain much with a Crane 272H- get a cam with 112 or 114 LC to raise compression. You could also mill your heads .050" to take 10cc out of the combustion chamber- raise your CR up to 8.2:1. Summit Racing's K2801 would work well with stock heads.

Geno  

IMO, Summit K2800 would work even better than the K2801 on a 7.6:1 stock compression 350.  You need at least 400CID and 8.2 CR to use the K2801.

Also, put a stock cast iron 4BBL intake back on it.  The E-Performer is the wrong intake for your setup.

Craig  

thanks guys, had a look at the summit k2801 & k2800, they look like the rev range would be a little low to match my converter, was thinking maybe the k2802 with the 114 LC and rev range 2500 - 5000 rpm, how do you guys think this will hold up with stock heads ( for now until i find some) also would some one be able to advise on what lifters to get with either one of these cams, can i use stock valve springs?

You have no idea how much you guys have helped, 99% of australians think pontiacs are the same as a 350 chev and try and sell me SBC parts and this is in auto performance stores, you get pretty pissed after going to a couple of stores

Ryan  

Ryan,
IMO the Summit K2802 is too much cam for your CR- it will make your engine run like a dog since it will bleed off too much compression at lower rpms. The Summit kits come with lifters, so they are a good deal. Stock springs were designed for low lift Pontiac cams (around .400), so anything over .450 lift is pushing it. You will have to get better springs if you want to run a cam with more lift than that.

If you want your 350 to run hard you should consider swapping heads (running those early D-ports). PM me if you want me to help you find some. If you want to run stock heads you will need to mill your heads down .050" to gain some compression- 8.2:1 isn't great but will let you run lower grade fuel.

You will also have to convert your non-adjustible valve train to an adjustable one. Pull the pressed in rocker studs out, tap the holes for screw in studs (if they're screw ins you're good to go), install straight 7/16" rocker studs with polylocks and you can now set your valve lash.

I personally would stop going to your local speed shop if they can't tell the difference between a Chevy and a Pontiac. The internet is a great place to get info, parts, and advice. It's tough, but Pontiac motors are just a strong as any other Detroit engine- you now can also get forged rods, cranks, and aluminum heads too.

Geno  

I agree the summit k2802 is a little more cam then you need I would recomend looking at the lunati .458 lift  P#00072LK bracket master2 cam instead. it will give you better performance then the summit cams also if you do have the stock 94 heads your compression will be 8:1 instead of 7.5:1.  
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