[Norwood]

1975 Formula 400 4 speed, 355 rear gears, motor is 100% stock with Quadrajet and 6x8 heads, true duals with Ram Air exhaust manifolds.

Looking for a cam that might provide a bit more power as well as good derivability. Anybody have any good recommendations? I have no plans for any other improvements other than a cam swap right now. Thanks for your thoughts...

[Held for Ransom]

Probably get a better answer in the Pontiac-Street section.

A little better than stock would be an "S" or "T" (RAIV) cam. Any way you do it, get your carb. updated for todays gas.

[71HOT/A]

The IV cam has too much duration and overlap to benefit a low compression engine. Milder durations, earlier intake events and an increase in lift would work better. I've put a couple together like this, a 2 something auto and a 3.08 4spd. Both were a lot more fun with more bottom and mid range but fell off fast around 4800-5000 rpms.

[Norwood]

Como cams recommended this one, thoughts?

http://www.compcams.com/Company/CC/c...csid=1201&sb=2

[71HOT/A]

Yeah, that's the stuff. Fools the engine into thinking it's got more compression. I would see if I could find something with a hair more duration to extend the power range with that gear. Try to stay with those separation angles and intake centerline. The idle will be rougher than stock along with less vacuum but not enough to affect the brakes.

[Norwood]

go up one and i'm there?

http://www.compcams.com/Company/CC/c...csid=1202&sb=2

[rexs73gto]

What are you going to be using the car for, It's best to know that before ANY cam is recommened for anyone. What is the car going to be used for? Street, strip, both or just a dedicated cruisier??? When you know what the car will be used for & wheather the car is a stick or an auto, also the rear end gears. Now the big questions is what is the engine built with now. What heads, bottom end, carbaration, stick, auto rear gears. Let us know & we can help you out better.

[Norwood]

Originally Posted by rexs73gto

What are you going to be using the car for, It's best to know that before ANY cam is recommened for anyone. What is the car going to be used for? Street, strip, both or just a dedicated cruisier??? When you know what the car will be used for & wheather the car is a stick or an auto, also the rear end gears. Now the big questions is what is the engine built with now. What heads, bottom end, carbaration, stick, auto rear gears. Let us know & we can help you out better.

Just driven around...rest of info is at the top. Thanks

[Held for Ransom]

One member (2002Z4CSS) has a similar combo and loves what he did. He did change out the torqued nuts for small block Chevy crimp nuts.
http://www.forums.maxperformanceinc....d.php?t=728848

[PunchT37]

I used a Crower 60240 in a stock `79 T/A with stock springs. No problems.

http://www.crower.com/index.php/sear...0240&x=13&y=11

[71HOT/A]

That second comp cam , the 222 should be really nice. Should have great bottom end and mid yet still pull a little farther on top, 3.55s aren't real low but they're not 3.08s so I think that would be a great choice. If the car was an auto the melling or the comp 221 would probably work better. I would check the piston to valve clearance before I ordered, just to be safe. Good lifters, poly locks and lube. New quality timing set, I would advance it 2-4 degrees and you should be grinning. Oh, I forgot, you'll need new rear tires soon.

[2manyT/A'S]

Just put an 068 in it..........70 RAIII & 71-2 455HO.......You'll LOVE it.

Mellings makes a blueprint for $100 bucks

[Norwood]

This thing is really a stone with this 7.6 to 1 commpression, but the reguler gas part is good. Just trying to wake it up a bit. The 068 will work with the stock valve springs?

[2manyT/A'S]

I stuffed one in a bone stock (other than dual exhaust) 75 400 4bbl.TH 400 about 20 years ago.

(with new lifters,timing chain & BBC chev rocker studs)

STILL woks really good....passed smog (at the time) supports the A/C compressor at idle...

With your 3:55 gears. & 4 speed.....you'll love it......AND it's OEM.....

[Rocky Rotella]

If you can swing the cost of a hydraulic roller (which would include a valve spring swap), a mild custom grind would give you the greatest combination of performance and drivability. It is, however, pricey.

If you want to stay flat-tappet, then I'd suggest an Melling 068 replacement (as noted above) or even a Summit 2801.

[Norwood]

Flat for sure......I thought that some of the newer cam designs might be much better than the 068 in this low compression application.

[71HOT/A]

I forgot to mention you should check with comp on the stock valve springs working with the 222. That would still be my choice, mid-late 70's have so little compression that they need all the help they can get. The 222 has more lift than the 068, about the same duration and the lobe separation and centerline are optimized to raise dynamic compression thereby boosting low-mid power. The 068 will work but will not pull as hard down low, on top it may out power the comp but I would not count on it.

[ta man]

If the shortblock is healthy..I'd swap the heads and up the compression...there are many good available iron heads out there that can be bought at a decent price.
I'm doing the same to my 76 455 4 speed car....stock the compression is only 7.6 to 1 ...going to just over 9 to 1 will make a huge difference.Depending on budget the cam could be also be swapped to compliment the higher compression..but will be like a totally different car with higher compression.

[Rocky Rotella]

Originally Posted by Norwood

Flat for sure......I thought that some of the newer cam designs might be much better than the 068 in this low compression application.

I do think there may be better modern cams, but the quicker ramp action associated with them may be too much for the stock valve springs.

If you're simply wanting a cam and lifter swap and not interested in swapping valve springs, then the 068 and 2800 would be my recommendations.

If a spring swap doesn't both you, then a modern grind like that the guys mention would be a better choice.

[Norwood]

The truth here is the short block is very healthy as it is really the WS motor in my Trans Am. Had a bad Head gasket and since I was planning on pulling the heads over the winter and getting hardened seats put in I decided to just do it now. As to keep on crusing for the summer I pulled the 6X8 heads off the engine that came out of my 75 Formula and put them on hence the 75 Formula reference. The current cam is a RAIV cam which ran very well with the 12 heads. The car went from a nice preforming car to a total stone. It still runs great but I'm not going to beat Brewsters 455 HO with it. So I thought a quick cam change would be to my liking. I don't really want to do the springs so I just might go with the 068 as I should have back in 1985 when I built the motor. AND NOW YOU KNOW THE REST OF THE STORY.....