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thumpr with stock heads?

17K views 17 replies 6 participants last post by  Studebaker 
#1 ·
First time poster, long time reader. Like most people on here, I have somewhat of a small budget to work with. And like most people I love the sound of a nice choppy idle. And like probably more people than would like to admit, I have no intention of ever going to the dragstrip, hell the closest one is 100 miles away. So after much thought, I did the most logical thing in my mind to my 350 sbc powered 1980 Trans am to enhance my trips to town, and that was installing 4.10 gears. It will spin the tires as long as I want, and put a grin on my face when I accelerate to 50-60 m.p.h. as I'm hauling one of four of my kids to school, ball practice, dance class, etc. I don'.t care about horsepower, just want that cool idle. what has to be done to my stock 882 heads to run the small thumpr cam?
 
#2 ·
Welcome to the site :welcome: . What cams have you been looking at do you have any ideas yet? Myself i would'nt put any thumping cam in a basically stock engine with a few more upgrades. Like heads change the springs add a set of studs and guide plates have the heads check out a possible valve job. Are you running a automatic if so do you have a stall converter thats something you should consider also. Is you car carburetor ?JMO

Cole
 
#4 · (Edited)
Your not supposed to but I ran a comp 262xe with stock springs on a 73 stock smogger 350. With the steep ramp, the proper springs are a good idea especially with the constant high R's you turn with 4.10s. The stock heads should be good for 500 lift.

I looked up the 279thumpr and it calls for a 2000 stall. You might get by with a stock convertor because of your gears.
 
#5 ·
phanline6.6 said:
Its a 355, flat tops, performer intake, 670 Street Avenger, headers, th350, stock converter. I just want a nice choppy idle with not alot of additional work. I'm a dirt digger, not a drag racer :D
Well now your engine it's not stock :D . What i was getting at was when you go changing cams with stock heads if you go to radical you will eventually drop a valve / rocker arm keep jumping off just a few things that could happen. Thats why i would at least add some springs to the stock heads. It's just when you go changing things like this it throws everything off the geometry, I have been there to much spring not good either. I have seen people try to add big cams with nothing else to back it up and wind up spending more money then they even considered i am just trying to help a fellow rodder out. Maybe someone else will come on and explain it better then i can. But i hope you got my point. You got a good start with your 355 i would either do my heads up right or buy a good set of heads ready to go or leave alone till i had the funds to do it right so that i did'nt waste my engine. Sorry to ramble one it's just you have to have a good top end. I am sure though you can find a good sounding cam that will work for you . Just trying to help and maybe save you some trouble down the road. JMO.

Cole
 
#8 ·
Heres one that should work and give you a decent rumble, Should work fine with your stock 882s. crane 274H06 with 218-218 duration at .050 and .450 lift on a 106 lsa. Or you can look into the VooDoo 262 about the same cam as the crane about the same specs . Still gonna need at-least a 2500 stall IMO.

Cole
 
#9 · (Edited)
the comp 268 is advertised as having a choppy idle. It is the high energy series so it doesn't have such steep ramps. Check out some vids on youtube and see if you find a cam you like the sound of that is stock head friendly (lower lift). Since you have the gears and convertor you might look into the "lift rule" circle track cams.

Summit also has some pretty good cams cheap.

duration will get you the lope but tight lsa gets you the pop corn sound 106-108. It can reduce the idle vacuum but build mid range. just for reference most stock cams have lsa of 112-114.
 
#10 ·
I had a friend that went with the comp 268 it's not very choppy not very noticeable at all IMO But you might like it dependes on how aggressive you want it to sound you can hear it but it just not to aggressive JMO. The crane and the voodoo cam i showed you are for a circle track engine which have certain limits they can go with lift and such. Either one should sound pretty aggressive. JMO

Cole
 
#12 ·
Looks like it has pretty much the same specs as the other two cams i showed you. Don't see why it wouldn't work still gonna need a converter. Be nice if you could hear one i would do what Sam bo said search youtube listen to a few get a better idea anyway. I have never used a summit cam before.

Cole
 
#17 ·
Before I'd use a poser cam, I'd just as soon retard the ignition and pull a plug wire. Instant 'lope' LOL

No, but just select a cam w/about .450"-.480" lift, 230 degrees-plus duration @ .050" lift and a 106 LSA. That way, when the fun wears off of sounding fast you can get those Vortec's and maybe actually BE fast. Or at least faster!
 
#18 ·
right cam.

I take it this is a daily driver? You are right to research this, as the camshaft is a critical component in the overall engine performance. The 882 heads are not very good and leave a lot to be desired. I have used a Comp Cams high energy 268 on a simular combo with great results. Great street cam with good driveability. I would however suggest the entire K kit. Springs should be changed, proper valve springs are a must. Also screw in rocker studs. Higher lift and faster ramp speeds can cause stock press in studs to wear or pull out. Good luck with your project!
 
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