building a 350 to ho specs? am i doing it right

i got a 1971 pontiac 350 in my 81 trans am it has a eldebrock performer intake and 650 carb with hei ignition and hooker headers with a auto and 3.73 gears i have the number 94 heads that are 90-96 cc on it right now and i tore it apart to inspect the cam and lifters 1 lifter came apart but i put it back together and reinstalled it all and it runs good now but the cam and lifters are wore and in need of replacement i was thinking of building it to 350 ho specs with a 68 cam, i picked up a set of redone #47heads off a 69 350 that are 72cc so id have higher compression but i was thinking of taking 8 ccs off those heads to make it 64cc and change the valves to 2.11/1.77 just like the 350ho my question is is there any better cams out there for my setup? should i do any porting to my heads? and should i get screw in rocker studs, how much would a place charge to change the valves over and make hardened valve seats and maybe even change it to screw in rocker studs, im just looking to have around 325-350 hp so my car can be in the low 14s maybe high 13s is that possible with that setup?  

I'm doing the same thing man, I wanted my motor to either match or surpass the 68 or 69 350 H/O. I couldn't get a hold of #18 or #48 heads which are H/O heads for the 350 but what I did was i found #62 heads off a 68 400 and got them on b/c of bigger valves and I don't know if I raised compression or not, wish i knew but also got those bored over for bigger valves. I also slapped in a 465/298 cam in there (which is the biggest one i could fit in there w/o roller rockers). Other things I added are an edelbrock performer intake, 650 cfm edelbrock carb, jegs headers, and a tight 2,500 stall torque converter. The guy at the machine shop told me i should be making around 350 h/o spec, if not more. I sold my #47 heads but I think what your doing should be fine. I would recommend getting pushed in studs, and whatever cylinder head work you want done, just depends where your income takes you. Thought I would just get my word in, so far it does sound like u r going into the right direction  

Jarrett, your combo sounds good, there are newer cams that have similar specs to the 068 that have more optimized action. Often they will give you a better idle and torque than the old grind. But the choice is yours. As for the larger valves, I wouldn't waste the money for the bigger exhaust valves, it's till only 350 cubes, most Pontiac builders agree that the 1.77" valve is only necessary for really big or really hi-rpm use. Also when considering the bigger valves, remember that Pontiac chamfered the tops of the bores to unshroud the large valves in the 350HO, when they switched to the 2.11 across the board in 75 they chamfered the intake side only. Remember that the higher compression will require more octane too. I would think low 14's are attainable with this combo, it's all a matter of tuning and traction.
Steve  
A little help... 'cause we don't all have to learn the hard way!

thanks for the help i wont change the valves then but should i have the screw in rocker studs or just keep my pressed?? i have access to 93 octane and 110 octane locally so im not to worried about the octane would taking some cc's off the heads for more compression be worth it? will the 068 cam give me a somewhat choppy idle in my 350?? what would i look for in a cam for more optimized action that has similar specs to the 068?  

Jarrett, as far as the studs go, I would upgrade to screw in studs while the motor is apart and go with a set of poly-lock adjustable rocker nuts so the lifter preload can be set. My 350 had previously had one head milled to correct a head gasket failure and the lifter preload on that side was way to excessive and it idled like prostocker. When I put poly locks on and set the lifters by the noise method like a small block Chevy, the idle smoothed out quite a bit and now it doesn't smell so bad at idle from the excessive fuel blowing past the valves. The 068 cam should give a fairly smooth idle, but Comp cams or Crane have more modern profiles available. Comp has a service on their site that lets you fill out a tech card and they will e-mail you with a cam recommendation. If you are honest and thorough when filling out the info, they can tell you exactly what will work best for you. Something like their XE262H should fit the bill.
Steve  
A little help... 'cause we don't all have to learn the hard way!

Ooops, I was looking at this post and for some stupid reason I recommended pushed in studs... I meant to say screw in studs!!! not pushed in lol sorry about that!  

I've got a 74 lemans sport coupe i've had for 20 years ' it has a 350 bored .30 over been balanced with trw forged pistons, .490 lunati cam sig earson valve springs , you need to use valve springs to match your cam. as for as your seat pressure. i got #17 heads off of a 69 350 , they are 265 horse heads but only 1.96 and 1.66 valves. a smaller valve will build more cylinder pressure than a big valve will. screw in studs are best but a pontiac head uses a 7/16 tappered stud, warrior products sells a stud with 1/2 threads, or you can healicoil the head , that's what i did.  

There are a few choices,heres what I did.I have a very clean 69'350/265 F,bird coupe that was just very little fun.I'm talkin 16.65 in the 1/4.First step was a quadrajet and c/i four holer from a 400,dual exhaust with stock manifolds and some turbo mufflers as i trashed the crossflow job.With a curve on the distributor this all got me to 15.20.This is alot so i was lookin to see how far this would go.Next were a set of 48's I bought off e-bay from a guy with the name of 67gto or somthing.I set them up with Ferrea 2.11 and 1.77's but I'm thinking it would have been easier to get the longer RAIV valves as hunting for a spring good for 520 lift with a low setup height that the Pontiac has would have been much easier.The only work to the heads was to gasket match and new guides.I used comp cams everything else but The springs were crane 99340's,300lbs open at.500.This is  about what i wound up with using the crane cam and lunati 1.65 roller rockers.Gets good now!It went 14.80 blowin the tires off.Couldn't get it to hook.Had to wait a few weeks as the trailer and tow rig wern't mine so i had no choice.Next trip with some sticky tires resulted in a few bogged out runs that showed potential.late in the day,loadin it up against the converter for all it had was good...14.07 best it went that day.A few weeks later ,with a set of hedman 3 tube hedders unkorked it was no change, but it was backfiring.Another pontiac racer with a timing light and some better q-jet knowledge bumped up the timing and did a few tweaks on the carb.It was good,13.36 with 28 psi in the tires.I didn't know that drag radials liked more pressure.At 36 psi it went 13.22 and this car has no posi with 3.73's and a fresh TH350.I'm sure that 12's are not going to be a problem and this will be where I start off the 2010 season.First thing is gonna be that neat limited slip unit from Richmond gear that you can slip in just by removing the rear cover and sliding the axels out.  

I guess you guys have to educate me? I realize the 350 is a good motor for the street and cruising but if you guys are going to race them why are you wasting all your time and money on such a low cubic inch poncho? There are tons of 400's and even a few 455's still out there for sale. These motors have a lot more potential for more power for the money just based on the cubic inches. Add a set of high flowing aluminum heads and you can increse your compression and make well over 400 horse very easy and still on pump gas. wow you will not believe the put you into the seat torque you will have.The 81'is a fat car and needs a lot more than 350 horse to get her in the 13's. The bigger inch ponchos would be a place to start.  

I guess it all comes down to wanting to use what you have. There are also tons of late 2nd generation Firebirds and Camaros running around with 350 small block Chevy's that can turn 13's, without aluminum heads (or aftermarket iron heads), it just takes a well thought out combo. Why should we need a bigger motor to do the same with real Pontiac power? Honestly? I mean, sure we can do it easier with a 400 or 455 and still be nearly stock, but a properly thought out 350 should be able to do the job with ease. Some of us just like to be different, that's why we drive Pontiac powered cars in the first place!
Steve  
A little help... 'cause we don't all have to learn the hard way!

PS: I'm also willing to bet there are far too many aluminum headed 400's and 455's out there that can barely break into the 13's, because nobody bothered to think about the whole combo! Am I right? Bet the guys who own them won't admit it if I am!
Steve  
A little help... 'cause we don't all have to learn the hard way!

+1 I agree with barney I have seen 455's get there but handed to them by a smaller engine like a 350 and 400.

Oh and then there's the awe effect when they ask what you got under the hood and you tell them and they do not believe you until they see the 350 cast in the side of the block.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

I my case It's a dumb question.It's a numbers matching car and to go with a different block would mean whatever I spent would not be offset by the loss in dollar value of the car by an  engine swap.yes I could swap it for a 455 and keep mine for the rainy day when i sell but the premise of the whole deal was to just see how far the project could go with what I have and yes I have spanked some bigger inch deals with it.To be honest with everyone here the Butler stroker setup and some 4-bolt caps looks awful interesting.I think he's getting the 350 up to 413?Am I right?If you actually read my previous it would be apparent that I was just tryin to get the fun factor up in my 69'F,bird and had some success.I'm not a hard core racer.I really am a Mopar man but with all of them sold and the wife wanting a car SHE could drive,the Bird popped up for sale and the rest is history.It's very interesting in that it is very receptive of any performance mods I have thrown at it and frankly,It has my interest piqued.I'll keep the site posted.  

I understand if you have the 350 and want to work it it's no problem . I have always been a believer in more bore, more stroke, more power. The same mods you do to a 350 poncho and a 455 for the same money I would still always bet on the bigger mill all other factors being equal.The 350 chev is another matter all together. Those can be put together very cheap and easy compared to a pontiac just due to sheer numbers and aftermarket availiability.I've owned and sold a 3rd gen 10 sec. camero.There was no real challenge but nothing in the original block was stock and it was not street drivable either.Now if your punching out a 350 to 413 it's not really a 350 anymore is it? I guess technically you could call it numbers matching? I could care less about numbers matching or the barrett/jackson crowd so the 403 lays on the floor in the shed and a 455 drives the car. One area you may want to look at where I believe you will feel the power right away is in the intake. The stock cast intake needs to be worked alot to even come close to a Edelbrock performer but if you want real gains look for a performer RPM or victor. That will wake up your poncho and take alot of weight off the motor.Less mass to move the quicker you go,You didn't think they run the skinny's up front for looks did you?  

I agree, the same mods to a bigger motor cost the same as a 350, that's the beauty of our beloved Pontiac V8. It's also our curse as a 326 or 350 weighs roughly the same as a 455! Careful shopping can get you lots of great parts for great prices, I just bought a Performer RPM and 750 Performer carb with electric choke off Ebay for less than the price of the carb new. It may go on my 350 for a season or two but it is intended for my 400 (which may become a 455 via an Ohio Crankshaft stroker). I think the original intent of this post was concerning relatively mild street cars, not 12 second or quicker rides. My nearly stock 350 (only a cam change) runs mid 14's in the 1/4 at a street weight of 3960 lbs (79 Formula, non-AC, steel Rally 2's, full body, 1/2 tank of gas and my fat 290 lb ass in the seat!). It's respectable, driveable, fun and cheap. Not to mention the looks I get when I tell people what it is, they expect 400's and 455's to be fast but not 350's. Remember a short time ago when high 14's to low 15's in a 5.0L Stang was something to be proud of? Seems that since Hotrod magazine started calling drag cars with licence plates "street cars" and The Fast and The Furious" tried to tell everyone that those rice grinders were "10 second cars", now everyone thinks you have to run 10's and 11's. That's not how it was in 60's and 70's when musclecars were new or just "used cars", they were high 13's at best and typically 15-16 second cars. Sure there were some sharp tuners and drivers who were faster, but they weren't the norm. Just my two bits.
Steve  
A little help... 'cause we don't all have to learn the hard way!