# question for you engine builders



## Boomstick (Sep 13, 2021)

so i settled on the melling spc7 (068) cam for my 350 build... until a local pontiac guy suggested the spc3 (RAIII 744). the car is a 69 lemans, original 2 bbl xs code 350. currently it sports an edelbrock rpm intake and summit m2800 750 4bbl, pertronics flamethrower distributor. when i do the cam swap, i'll also be swapping in a set of '69 #46 heads with 72ish cc combustion chambers which should bring me to 9.5:1 compression or so. the trans is a stock TH400, and 3:23 gears in the rear.

thoughts on the spc7 vs the longer duration spc3 in this car?


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## coyote595 (Dec 4, 2019)

With the automatic trans, and I assume stock type converter and 3.23 gears, I would say that you would probably be happier with the SPC7. Fewer cubes makes a cam run like a bigger cam. Pontiac did not use the 744 cam with automatics, and later in the 69 build year, they used the 068 cam for all RA3 applications, even 4 speeds, and that is with 400 cubic inches, which would make the cam feel smaller than it would in your 350. It really depends on all the other components you choose to pair with it and your intended purpose for the car. Cam selection is a very personal choice.


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## Boomstick (Sep 13, 2021)

I didn't even think about the smaller displacement, bigger cam effect. I was just looking at number...lol... spc7 it is!!!

the car has a stock torque converter, stock trans and 3:23 rear (supposedly 3:23, i still haven't checked... might be 3:55 or higher). she pulls pretty nicely now and does smokey burnouts but more compression and bigger cam wouldn't make me smile less...lol... the motor is nice and tight for a car with almost 100k on it so i assume its been rebuilt at some point recently. im the 3rd owner. it doesn't smoke and has good cylinder pressure and did well in a leak down test performed by the shop I took it to to rebuild it that said "no, we wont rebuild it for you. it doesnt need a rebuild, you're wasting your money."

i still want a 69 428...


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## coyote595 (Dec 4, 2019)

Yes! I love the 428 engines. Back in the late 80s I helped my friend with a 69 Firebird put together a 428 with a RAIV cam and Rhodes lifters. That was a fun car! The 428 has great torque, yet the 4" stroke is not excessive, so it still likes to rev a bit. Very lively. His build was just a quicky overhaul with cleaned up cast pistons, as he was really budget constrained. I told him not to be revving it past 5500 RPM, but the thing liked to scream, and he became addicted to that feeling and sound. Wasn't long before the inevitable happened and he broke a ring land on one of the pistons. It was very lucky that he did not grenade the whole thing. We put it back together with some proper parts and it still runs to this day. Back then, I had a 75 Firebird with a 400 with RA4 #614 heads, 245/256 Crane solid cam, a TQ1 intake and 750 DP carb, While mine would beat it every time, I would say that his was much more fun to drive. His had power everywhere, while mine didn't really come on until about 3000 RPM. Pretty exciting from there on up though!


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## Boomstick (Sep 13, 2021)

personally, i think the 428 is the best engine pontiac ever made... the pre-557 400 being a very, very close second. never been a fan of the 455, but of course, id take a 455 over my 350 any day...

well, at least its not a 326...lol...


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## coyote595 (Dec 4, 2019)

I would be more inclined to do a 455 variant today than when I was younger. Back then, I like to hear an engine scream, and I still do, but my aging back always encourages me to pursue reliable, low maintenance power now. That being said, my latest car, like yours, still has the original un-rebuilt 350 with 70K miles. Runs like a top and uses no oil, but not much power. I am really struggling with what I want to build. For now, I just enjoy cruising around in it. I still have the engine from my 75 Firebird that I mentioned above. It spun a rod bearing with 40K miles on it during a drag race. It has been on a stand ever since. Life got complicated. Sometimes I want to just do the minimum to get it back running. Other times, I want to create a 434 by dropping in a 428 crank. I also consider using a 455 crank, but that has never really been my preference. Tough decision for sure. I am focusing on upgrading the suspension and drivetrain from the rear forward while I mull it over.


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## Boomstick (Sep 13, 2021)

i really want tire smoking torque, hence my love for pontiac motors. probably the best torque you can get without going diesel... i really dont hate my 350. as long as i can two leg burnout the thing off the line without using the brakes, ill be happy... maybe...

i had a 68 ra3 gto 4spd 4:10 rear when i was 19 (1994-96). that car saw several different engines in it including a 428 and a 455, that 428 was practically uncontrollable and scared the crap out of me. until i ventilated the block. the 455 was ho hum in comparison to the 428 and the original 400 ra3 that the car came with. i blew the 455 relatively quickly but my girlfriends dad had a junk yard so for $50 i could have any motor/trans/rear i wanted as long as i pulled it myself. $100 if he pulled it.that 455 came out of a convertible granville that had no title and needed a new top. I might not had been the brightest when i was that age but i was smart enough to pull the original motor and put it aside so i wouldnt blow it up. Its sad thinking back on the cars that i saw crushed and chopped up at that junkyard. he had a 69 judge that came in totaled that had had the motor torn from it in the crash. he also sold cars and had a real clean yellow 454ss chevelle that some kid bought and turned sideways coming out of the lot right into a tree and totalled it. my GF's dad towed it right to the back not 30 minutes after he sold it. my 340 duster ended up there after it spun a bearing, as did my grand national powered 81 malibu wagon i totaled. i bought that wagon for $250 all it needed was a crank pulley, the guy that built it must have forgotten to tighten the bolts...


boy those were the days...


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## geeteeohguy (Feb 2, 2008)

Your choice of an 068 speck cam in that 350 with those heads is a sound one. Had a '65 GTO with a similar cam and a 326 out of a '64 Lemans and it ran almost as hard as a 389. Years and years ago, another buddy of mine picked up a rough '65 GTO with a 350, 068 cam, and '65 tripower on it....car was a TH350 conversion. That car was scary fast. 350's and 326's are good engines and have that magic Pontiac low end grunt that can surprise people. Good luck.


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