mikey dragster

cam, question guy's
i bought a 91 firebird t-top'sanyway: it's got a 1974 400sbc in itwith intake350-5425 with 2 tbi's from a 350 truck engine adappted to it. they got injector spacor's and every thing like that all ready done. it was a fun car tell it spun a rod bearing. so know i'm rebuilding it. i swapped the 3.73 gears for 4.11.
it got a 700r4 from a gmc 3500 rebuilt with shift kit.
it sopun the bearing about 4 months after the gear and tranny swap so now i'm building the stuffing out of it. here what i need to know should i use the 318*cam or the 328* cam which would be the best choice cause the old 292* cam wasn;'t all that hot.so those are the 2 cam's i was told to choose from. so what would you guy's sugest. so far best run was 13.88@107mph. i'd like to see about 110mph and about 13.6 time zone. already got a 10.2:1 comp ratio.so it will run good on 93octane. the block and lower end is done. i'm at the cam and head's piont now. so 318* or the 328* cam anyhelp would be nice.

Greed4Speed

I ran a 12.90 in a 70 SS 350 in street trim with the Comp Cams 292 magnum cam w/ ported 292 angle plug heads, TH350, 10" converter and 4.11 gears. I don't think it was the cam holding you back.

Your best best you be to call comp cams cam help tech line. Its toll free and you can't go wrong with advice from people who do nothing but work with cams. I think it is 1-800-cam-help. The # is on their website and in magazines.

mikey dragster

I was told by crane cam to run 318* 675 lift or a 328*with 635lift.
they claim either cam would do what i want and more.depending on the rest of the engine. they where leaning more towards the 318* cam then the 328*. they said the 328* might be a bit much but the 318* would be ideal. it would lauch fine but around 93mph at 4,800rpm's it start to run out of cam.

mikey dragster

it was set a stock shift piont's so it would:
1st to 2nd at 4,300rpm's at 27 mph,2nd to 3rd at 4,100 at 50mph
then it would run in 3rd till 5,700rpm's at 107.3166mph at finish line. but around 93mph at 4,800 rpm's it would fade fast. so just a few feet before the 3/4 piont of the 1/4 mile it was all out of steem, and it sat and reved to the finish line.
so i assum it the cam. tom lazar who raced the super stock amx's ran it a few times and he said it runing out of cam. i was told by previouse owner it was a 292* cam but tom thought it more like a 288* cam but he it could be a 292* but he is 80% sure it's a 288*,and only 20% sure it could be a 292*.

nape

I doubt it's running out of cam. TPI setups are known to run out of steam about where you said. They make great torque down low, but I've heard they're out of top end by 5000-5500.

mikey dragster

nape this ain't a tpi engine this is a tbi setup on a 400sbc. read trist post to explain the engine.

Greed4Speed

Like I said, I ran my 292 magnum (.501" lift) up to 6000 RPM and got a best of 12.90 sec. It would pull to 6200, but I didn't like to push it past 6K. So, I doubt it is the cam if it is a 292. Even the 288 should pull close RPM. I known several guys running cams w/ that advertised duration in modified stock circle track classes.

I'd look at your ignition, induction, and heads. If you're running 2 TBI's it sounds like the early 80's crossram. If so, there is your problem. It was designed for a 305. The stock HEI isn't much good over 5000 RPM either. Also, what type of heads are you running? Another thing to check out would be your computer, is it the original? None of them are calibrated for a 400. Might try posting in the 3rd gen forum.

As for cam choice, if Crane suggests one...try it, but thats a WHOLE LOT of lift just to get to 13.6 sec. With that much cam, you should be in the 11's. I'd ask comp cams for a suggestion just as a second opinion. I ran a 13.36 in the same car when I redid the engine w/a Lunati street master cam (.507" lift) and stock 186 casting heads w/matching springs.

mikey dragster

ok man i'm looseing patience here it's not a crossram. it'a an eldbrock intake #350-5425 go to jegs.com and check it out it ain't no crossram. computer was reburned everything is set to fuel the 400sbc. my restriction was the stock 400 head's now it will have dart2 head's.and i did post in third gen forum check it out same post topic as this and i restarted it as 91 firebird 400 in third gen as well.

mikey dragster

and for another thing the crossram your talking about is called a crossfire: it has 2 1bble tbi's that sit at oposite corner's from each other. my intake ahs 2 - 2bbl tbi's siting front to back. and no it ain't a ramtunnel either. it's dual quad intake with 2 bbl tbi's from 454 engines in 1 ton truck's with 350 tbi injector's in it.

Greed4Speed

The fact is I ran a 12.90 with a similar cam and decent heads, and a 13.36 with a similar cam and stock heads. If all you want is 13.60 you don't need a larger cam and if all you could run as a 13.88 the problem is elsewhere.

I always enjoyed running guys like you on the street with huge cams in their cars because 98% of the time they were over cammed and thus easy kills.

BTW it isnt called a ram tunnel, its a tunnel ram, and the crossfire was a crossram. Crossfire is just a name that GM put on it. Like positrac, GM just gave their limited slip that name.

mikey dragster

i know but on this time out for summer of 04 it will now have dart head's instead of stock 400 head's. and now it's got better tire's235/60r15bfg radail t/a's for 295/50d15hoosiers.
cause it did slipp lot and traction bar's will be added as well.
the new is going to be a 292*with 575 lift with 2,800 stall.and i sswaped 3.73's for the 4.11's so it should be in the 12's were it should be.

Greed4Speed

The 292 I ran had only .501" lift.

mikey dragster

well good for you i'm going to use the 292* with the 575 lift. why you think think it won't work out for me.
should i try and get a 292*675lift.