Hi,
I have removed the front fenders, grill, radiator, etc from my chevelle in an attempt to makeover the front half of the car. Since I had the water pump, alt, PS, etc off it occured toe that if I were going to swap cams, now would be a good time to do it. My questions are, if I put in a pretty mild cam, will I need to change around the rest of the valvetrain (rockers, pushrods, etc), or can I reuse the stock parts? Also, I need some help in selecting a cam. I am on a super tight budget (college student) and cant spend a whole lot of money on the swap. The engine is a stock 1972 350ci, originally with a 2bbl carb. It now has a 1406 Edelbrock carb, performer rpm intake, and headers. I believe compression ratio for these was around 8.5-8.75:1. Bottom end is completely stock, never rebuilt. Turbo 350 tranny with stock converter, 2.73 open diff, and a 28" rear tire height. This is a daily driven street car, I am just looking for a little more oomph than what its got now. I am planning on rebuilding the engine completely in about a year or so, but I just want to make it a little more fun to cruise around in before I can do the whole rebuild. I was thinking about something in the area of 204/214 @.050, .420/.442, with 112 deg. separation. Any help is greatly appreciated. Thanks!
Fat Jonny

I think you'd be OK with a cam like that. When I was a kid we swapped in mild cams all the time without checking anything, and no one I know of ever had a problem (except for lost power from mis-matched combos).

I do recommend that you verify your compression ratio to be sure that you're using a well matched cam. Otherwise, you should have no trouble with the swap.

Fat Johnny
Was in the same situation (going to show my age here)back in the mid '70's. Had a Black '74 Chevelle 350 small block, Turbo 350. Did the dual exhaust, Intake/carb and then installed the 327/350 Hydraulic cam (222/222 @.05 .447 Lift on 114 LSA). Had a nice lope at idle, sounded mean. Car became a total slug. Eventually changed the rear to 3:73 gears, then it flew. I had a buddy who had a '70 Mach 1 with the 351 Cleveland/4 spd. He used to blow my doors in at will. When I changed the rear, it was a close contest. If you only have a limited fund - change the rear first. For less money than the cam swap (at this point you will probably need new springs, guides, who knows what) you can put in a set of gears. I wouldn't even worry about a posi at this point. A cam swap in that motor will be lucky to add 20 - 30 HP and mainly only at the middle and top end. And with the low compression of that motor you will actually loose a lot of overall grunt. Go with 3:73's it will feel like you added 100 horsepower in the engine's current operating range. Then you can always change the cam out when you get around to rebuilding the engine and match it to the rest of the combination at that time. If you are not driving a lot of highway and just around town, you could even go to 4:11's.

Jonny,thats a very sensible cam you selected and would work good for your setup.

But if it were me i would go with a little more cam like with approx (+- ) 210-214/216-220 dur @.05,.430/.440 lift,112-114 Lobe separation angle but no more with your 273 gear.

I am currently running a crane flat tappet hyd cam (210/216 @.05,.440/.454,114 L/S) in my basically stock 88 montes ss with a apporx 8:75-9:0 compresison in the stock 305 (50 cubes less) that idles rock smooth and runs fine with again 50 less cubes. Your cam selection is very mild and would work ok but with your 50 more cubes, better intake,carb & exhaust just a little more cam would really wake up your combo without loosing driveability. A cam in this range would stll allow use of your stock valvetrain componenets by staying under .450 lift according to what i have read by the experts concering whats a safe valve lift for stock SBC valve train componenets & pistons.

But please,anybody,correct me if i am mistaken on what lift is ok for stock run of the mill SBC valvetrain componenets & pistions of the late 60's to mid 70's era.

I also agree with the above reply that if you ran a cam in the 222 dur area (like 327/350 hp) it would be sluggish on the bottoom end with those 273's. A real nice comprimise between 273's & 373's (use too much fuel) for your mild setup would be 308's,323's,331's (hard to find),342's (max for street) unless you run an overdrive trany like a 2004r or 700r4 with lockup then 355's,373's,and even 390's become real nice wirth reasonable cruise rpms when locked up. (I'd go with 373's with a 2004r for your mild 350)

Also,keep in mind your motors 33 yr old springs would likely hold down your top end HP & RPM performance,springs are cheap and i would replace at least the springs and valve seals while your at it. When you go to a higher lift cam on old valve seals the valves and pushed further
down into the seals which can destroy them. This happens becasue part of the valvestem that has never been pushed down into the valve seal & guide that has old dirt/sludge on it now is pushed down further with the higher lift cam into whats left of your old seals ripping them up and as a result will use more oil your motor may smoke & possibly foul plugs with oil from time to time so keep this in mind.

Scott

FWIW, I ran the old -151 cam in my 10.25 to 1 CR. or so, L-48, 350 motor for several years AND it ran great, but I figure anything past about a 270 advertised duration and I had better have compression up around 9.75 to 1 or so b/c like was said, lower compression turns a motor with a larger then stock into a slug!

If you add tall tires AND have automatic or "high speed" road gears to an 8.5 to 1 CR. stock motor, she won't hardly get out of her own way!! But get her up above 25 to 3000 rpm in the lower gears and it will help her come on but that doesn't help in a drag race, only a roll-off race...

pdq67

PS., stock CR. for the -151 cam was supposed to be 11 to 1!!!!!

pdq67,
Forgot the numbers, I assume the -151 cam is the 327/350 cam reference. Even with the lower compression motors it really did run strong anyway. Of course by today's standards the advertised duration would be much shorter anyway. I still think, wants more power, limited funds, going to do a complete rebuild within a year, leave the motor alone at this point. For now, Good tune-up & rear end gear change.