[maxpowerta]

Hey guy's, I'm in the middle of putting together 1973 350 that I've had kicking around my garage for the last 20 years and need some advise on which cam to use. This is a relatively low dollar build so It is staying stock bore with the factory pistons,rods, etc. However in an effort to get the pathetic factory compression up a bit I did have the block zero decked, and had the 46 heads cut 0.040 thou but with the huge chambers i started with they are still only 89cc. I have the cometic 0.027 350 bore gaskets that I am gonna use but even with all that i still only calculate the compression at around 8.6:1 so my question is this, I have this cam LUN-10510702. But my concern is that it won't work great the low compression i have so would i be better off with the
LUN-10510701? When it's all complete it will be going into a 1991 fire-bird with a 700-r4 and i believe 3:23 gears.

[pastry_chef]

I'd go with the smaller 10510701

[phil400]

Summit 2800, don't get cheaper and Squidward has run a 350P Low 14s with that cam. Works with all stock valvetrain, even press in rocker studs.

[77 TRASHCAN]

Sealed Power CS641. It's supposed to be the 066, or used to be...

[HoneyHush]

If it were mine I would go with the 702 cam. The car is light weight and geared good. I think people under build P350’s. Every one I have had ran really good with headers and a good exhaust. The last one went into a 78 trans am that had 4.10 gears and a 2500 stall etc and that thing surprised all of us. It would easily outrun our buddy’s bolt on and geared 90 Mustang Gt. That 350 was stock out of a 72 firebird. We just put a 68 intake and a good qjet on it. We always wanted to cam one up with some ported heads and see what it would do but it seems Pontiac guys don’t mess with them for some reason.

[ponyakr]

The Voodoo cams would definitely increase cyl pressure in the low CR engine. But, if you still have press-in studs, those cams MIGHT pull one out. Paul Carter has posted that the Voodoo cams need more spring pressure than slow ramp cams. So, more spring pressure, along with the extra lift & steeper ramps, might not work with press-in studs.

But, if you have screw-in studs, a Voodoo would produce more power than the Summit 2800, but cost about twice as much.

Another option might be an 068 clone, such as a Melling SPC-7. Low lift & slow ramps. Some 350HO engines came with an 068. The only low CR engines I know of that came with the 068 were the 455HO engines. Assuming an 068 might make decent power to 5000 rpm, in a 350.

Anybody here have experience with an 068 in a low CR 350 ?

[455abody]

I have a set of 69 350 heads I believe they are 9.2 compression if interested. Nice looking car!

[Squidward]

Originally Posted by phil400

Summit 2800, don't get cheaper and Squidward has run a 350P Low 14s with that cam. Works with all stock valvetrain, even press in rocker studs.

Thanks for the props! But I hit 14.9's with the 2800, and 14.0? With the 702. 702 build definitely has easy 13's in it, and is surprisingly streetable, better than I thought it would be. I run 68cc heads with that cam, tho. You need to have the right head setup with seals/springs/studs to handle the lift.

The 2800 is a cant-go-wrong for a mild street build. It's fun, but keeps build cost low. It did 14.9's on a bone stock 69 350p, with stock 47 heads. It might have done even better with deeper gears and looser converter.

[maxpowerta]

So just a bit of clarification, the #46 heads are unported but they have been gone through at the machine shop where they were converted to screw in 7/16 studs, had a basic valve job done and were set up with the lunati 73949-16 springs. When i started this project i was operating under the belief that #46 heads were 89cc's out of the box so i figured cutting them 0.040 would be perfect to get me where i wanted to be. I should have cc'd them first because apparently the plain jane normal 46's were actually more like 97 cc's, and I'm guessing only the GTO's got the smaller chamber heads. I am pretty much committed to using these heads so I need a cam that will optimize what I've got.

[72LuxuryLeMansLa.]

Originally Posted by HoneyHush

If it were mine I would go with the 702 cam. The car is light weight and geared good. I think people under build P350’s. Every one I have had ran really good with headers and a good exhaust. The last one went into a 78 trans am that had 4.10 gears and a 2500 stall etc and that thing surprised all of us. It would easily outrun our buddy’s bolt on and geared 90 Mustang Gt. That 350 was stock out of a 72 firebird. We just put a 68 intake and a good qjet on it. We always wanted to cam one up with some ported heads and see what it would do but it seems Pontiac guys don’t mess with them for some reason.

Easy enough, $ per cubic inch...… It cost the same to build a 350 that it costs to build a 455. And, building a 350 you will need to spend money on custom pistons and probably head gaskets....Personally, I would love to build a P350 and put it in an old Chevy truck.

[gtofreek]

Originally Posted by pastry_chef

I'd go with the smaller 10510701

I would agree with this.

[SRR]

I did this with a P350 in my 70 Lemans Sport. The lower end was already .030 so I bolted on a set of 62's (stock 11's broke a rocker stud) 2 to 4 barrel stock intake with a Q-jet, dual exhaust, not sure what the cam was but probably a Melling SP-7. I felt like the car gained a 100 HP! What a difference. I had 3.23 gears also.

[PunchT37]

Originally Posted by HoneyHush

I think people under build P350’s. Every one I have had ran really good with headers and a good exhaust. The last one went into a 78 trans am that had 4.10 gears and a 2500 stall etc and that thing surprised all of us. It would easily outrun our buddy’s bolt on and geared 90 Mustang Gt. That 350 was stock out of a 72 firebird. We just put a 68 intake and a good qjet on it. We always wanted to cam one up with some ported heads and see what it would do but it seems Pontiac guys don’t mess with them for some reason.

Not everyone. Back in the late 80`s, early 90`s, we had a `68 LeMans with it`s 350. We put 061 heads on it. It had the Crane 310 cam. 236 at 50 with 485 lift. T1 intake with a 750 holley. Would hold its own in most street races back then. Course, it had an A1 2600 stall with 390 gears. Car had 10 inch Centerlines with N50/15`s. Ladder bars. Yeah, we were baddass. We finally broke 3 pistons and spun #3 main after booze and many times to 7 grand. Good times.

Forgot to mention, car had a fiberglass front end. So, car was fairly light.

[ponyakr]

As has been posted here & on other Pontiac forums, you can build a P350 with decent power. There have been several '74 GTO Stockers run in the 11 sec zone, and at least two P350 powered Super Stockers, in the 10's. A Pontiac friend won lots of dirt track races with his home-built P350.

A '74 GTO Stocker was #7 qualifier at this weekend's div 5 race, with an 11.158 ET. That ain't too shabby, for unported factory #46 iron heads, iron intake, 750cfm Q-jet, and a flat tappet cam with only .388/.424 lift. And YES, I know this is a purpose built race car. But, it's powered by an NHRA legal P350.

http://www.classracerinfo.com/Engine...8&MAKE=Pontiac

The problem with the P350 is the small bore size. Nowadays, it makes forged pistons & good head gaskets expensive.

Easy to get well over 400 hp, with a storker assembly. Ace got over 450hp with this 4" stroke build.

https://www.hotrod.com/articles/hppp...-engine-build/

Near factory spec 350HO rebuild made 330hp.

https://www.hotrod.com/articles/hppp...-engine-build/

So, I don't see why a lower CR stock stroke P350 build, with the small Voodoo cam, shouldn't make similar power.

Anybody here have dyno results of their P350 build ?

[maxpowerta]

Thanks to everyone that weighed in, I just ordered up the voodoo 701 hopefully that will compensate some for the lower compression.

[shoebox1.1]

I’m doing a budget 350p for my 76 ventura. I’m kinda excited about this combo cause it’s super cheap ( friends donating parts)

[PunchT37]

Originally Posted by shoebox1.1

I’m doing a budget 350p for my 76 ventura. I’m kinda excited about this combo cause it’s super cheap ( friends donating parts)

At least yours should have screw in studs already. So, a little cheaper at the machine shop.

[shoebox1.1]

They do. 092 heads with screw in studs. Little pocket porting too I think. 221/470/108 Howard’s cam is high on the short list

[Cliff R]

A 350 cid engine (low compression) build is going to be happiest with a stock or very close to stock size cam in it.

I've done truckloads of low compression ratio SBC builds for pretty much "stock" applications over the years (still doesn't qualify me for "guru" status according to some trolls here) and have found the best cam for them is the plain old Speed Pro CS-274 grind.

Most folks who do SBC's "upgrade" to the legendary "RV" cam which is basically a duplicate of the 2800, 204/214/112. However, in a 350cid build in the 7.7 to 8.5 to 1 compression ratio range the smaller cam is a LOT better in the "normal" driving range. Dead smooth idle and tons of power (torque) down where you need it in the 1000-3000rpm range. The only way to make the 204/214 cam as effective is to add apprx one full point of compression. I'll add here that most folks actually lower the compression as they install much thicker head gaskets (SBC's used a .020" shim well into the 1970's) and many of the pistons they source out end up pretty far down in the holes at TDC.

Just had a conversation yesterday with a customer who removed the 194/204/112 cam from his 350 and replaced it with the 204/214/112 "RV" cam during an engine rebuild. He noted that in his application (1 ton dually Chevy truck) it doesn't work nearly as well up against the stock converter and in the "normal" driving range where his engine speeds 99.9 percent of it's time. He says it's much better past 3500rpms or so, but pretty much a "slug" off idle and down where his engine spends most of it's time. He also saw a pretty significant drop in fuel economy.......FWIW.......Cliff

[track73]

I vote for the 2800.