I need cam help and any advice or opinions

[sev85]

Hi guys new to the site and need some major help on my cam im getting tomorrow!!!!

For starters i have what i believe is stock 350 mid 70s-late 70s block with flat top pistons, 462624 heads 76cc combustion chamber i think 200cc flow 2.02 intake/1.6 exhaust valves, very light porting done, a edelbrock rpm performer air gap intake with a 4 inch high rise and a mr gasket one inch spacer, a holley 3310-3 750 cfm vacuum secondaries carb, hei vacuum advanced distributor with 1 3/4 hedman long tube headers to a 3 inch outlet with 2 1/4 inch dual straight pipe exhaust no muffler or glass pack, th350 stock transmission stock torque converter gm corporate 10 bolt front differential and gm corporate 12 bolt rear differential (gov lock) with 3.42 gears

I am trading for a gm performance cam P/N 24502476
Flat tappet with matching lifters
.435" Int./.460" Exh. lift
212 Int./222 Exh. Duration @.050"
112.5 Lobe Centerline

(Only info i can find online besides what the guy sent me up above)
This hydraulic flat tappet is used on the 350-300 and 330 HP special performance engine P/N 12355345, and 12486014. The duration at lash point in degrees (intake/exhaust) is 320/324; duration at .050" tappet lift (intake/exhaust) is 212/222 and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 435/460. Valve lash is zero/zero and lobe centerline is 112.5 degrees.

What rpm range will this cam give me? Am i gonna be able to run it with stock valve springs in my setup and can it still be used for street, light off road, light towing, and fun cruising?

Also any suggestions on a shift improver kits likw Trans Go (not a shift kit) that will tighten my shift pattern without slamming gears on the street and breaking tires loose going into second gear?

Please any info on this cam and my setup would be greatly appreciated thanks in advanced for taking the time to read all this

[INSIDIOUS '86]

Your heads at 76cc are killing compression. You need to find a set of 68cc lt1 heads and get your compression back. Then for a stock engine a 750cfm carb with a performer air gap with a spacer is quite big even for the new cam, esp if it's an open spacer. This cam will suit your needs fine. Should have a range of 1500-5500rpm.

You need to get your torque back. A 650vs carb will help cylinder fill in the low to mid rpm range and maybe less spacer. Smaller chamber heads will bump up compression and help all around power, I would also get some new springs only because old springs are a liability. Now most smog era engines have dished pistons which also kill power with low compression. As for a shift kit transgo does make the best kits so go with them. A 2000-2500stall converter will help improve things as well and help get things rolling.

Then when you do all this and break your gov loc get a nice posi that will hold some abuse.

[sev85]

awesome thanks the spacer is a closed spacer not a open one it has the individual ports for the holley eventually my plan is to junk the holley and get a 650 edelbrock probably or a demon as for the pistons they are indeed flat tops they are not stock just stock bore size someone installed them before i got the truck and i definitely plan to throw away these earlier 70s camaro corvette heads for a set of 68cc aluminum afr heads or possible some edelbrocks and i defintely plan on junking the gov lock and installing front and rear detroit lockers with chromeoly axles my intake is dual plane incase i forgot to mention it

as for compression how high of compression could i go before having to stop using pump fuel? and is there anyway to avoid a stall not much of a fan of them truck had a 1000 stall that was junk had to replace it with a stock one

unfortunately this is a slow process having two lil ones my son is 18 months and my new baby is due in march so this is kind of a piece together as i can find time parts and money gotta take care of my family first i just hope it will be somethin i can pass along to my son when he gets older

[manimal]

I would not go with the early heads....Flat tops and 76cc's with get you "ALMOST" 9.0:1...but more info is needed....was your block decked?(that will play a roll in your compression) If you want to raise your compression, get a set of VORTEC heads, but you'll also have to change your intake.
For a mild engine, that cam will work great. Your combination will probably run out of steam around 5500....I think 1 3/4" headers are a bit big for your engine,but that's just me. I'd run 1 5/8". Now if you get your compression up around 10.0:1,then I'd keep your headers...and even then it would be border line.
Like insidious said, put a 600/650 vac sec carb on it and smaller headers and go with it....OR>>>change the heads and intake,put a slightly bigger cam in,leave the 750 and headers and enjoy....too many choices.
It all depends on what you want out of it. But for the least amount of coin, swap headers and carb and be done with it.

[deth_1970]

a comp xe268 would work with what you are trying to do, with it being a 4x4, it would give you good torque, and play well with those gears, i would go to a smaller header tho as the ones you have would help on top end but kill low end, 1 1/2-1 5/8 is what I would do,
http://http://www.compcams.com/Compa...x?csid=73&sb=2

[ol_skool_chevy]

Comp Cam 280H is my all time favorite cam

Look on youtube you can hear a lot of them..

[deth_1970]

ok after looking, the xe 268 h, 12-242-2 is what I would recommend,
http://www.compperformancegroupstore...ory_Code=HFTXE

[sev85]

I rechecked my headers they are infact 1 5/8 the older heads came with the truck but I dont really have the money as of the moment to buy new heads so im stuck with these for right now I did get that gm performance cam with spec sheet had the lobes checked and the grind numbers it is what it was claimed to be I really appreciate all the help the block itself has not been decked just the stock pistons changed to flat tops after talking to you guys I think Iim gonna trade my 750 to my wifes uncle for his 650 holley with vacuum secondaries

My plan for this truck is to set about a 5500 rev limiter as I am hoping to have a idle to 5000 power curve and just use it for mainly fun driving thanks again for all he help guys im gonna install the cam and lifter kit this weekend and switch to the 650 carb and let you guys know how it goes thanks again for all the help

[INSIDIOUS '86]

A 2000 stall shouldn't be all that noticeable over a stock unless you has it more. But it depends on wether the stall was done with the stator or the fins or both. Flat top pistons and 76cc heads should have you around 9:1 compression if not less. Ding go with aft heads unless you like killing greenbacks. Profiler makes an as cast head that does just as good for about $1100 dollars. With that you can run 87 at 9.5:1-9.75:1 compression or run the quench down with a thinner head gasket. Which is always good.
I'm running 9.7:1 on my 377 bug I also have my quench optimized and a cam that bleeds off some of the dynamic compression ratio. The 268 cam is nice as is the magnum cams wich are older more conservative ramps. Those will need valve springs though. The lunati 268 cam is a great design and will net you good power and sound and drivability.

[sev85]

That sounds like a great plan it will be later this year or possibly next year before my wife will let me spend to much more money on this truck as in the last year alone I traded her favorite truck I owned (93 4x4 s10 ext cab power everything) for thistruck not running and until last month we have only drove it once and the front diff carrier bearings broke and than the following week the th350 blew and just 2 weeks ago the quadra junk gave out so this thing has maybe seen 10 miles since I got it in march of last year

But hopefully by next year can bore it out to a 355 with forged pistons and rods a steel crank a set of aluminum heads and maybe a more agressive cam and front and rear lockers