Hey all!
I have a 79 vette with a 350 (non-original) engine which runs perfect. But. it feels so underpowered compared to what I'm used to so I'm looking to liven it up a bit. I Believe the internals are stock (engine code VO428TBC, If that helps figure it out, I believe its a 76 or 78 block?) Here's a list of what I have done so far (performance wise):

• True Dual Exhaust
• 1 5/8" Full Length Headers
• Edelbrock Performer Intake
• Holley 650 Carburetor w/ Vacuum Secondaries
• Casting 441 Heads
• 3:73 rear end

I have a TH350 with I believe a stock stall converter (If I try to hold the brakes and gas to test the stall I push through the brakes, but it sits at 2200 right before it moves).
I am planning on doing a lot of drag racing during the spring, summer, and fall as I'm part of my schools racing team and race in Beat the Heat at the local drag strip, so I do want to hopefully get this thing into the high 13s or low 14s? As fast as I can go really on a high schoolers budget. A crate engine is out of the question for at least a year.

I want something that can roast tires just a bit when I plant my foot from a stand still and an occasional burnout. Right now on a hot summer day I can only get a tiny chirp. I am planning in the future to go to vortec or aluminum heads, but for now and the spring I want a good lumpy cam that'll liven up my engine a bit and sound awesome. I'm looking for a complete kit (cam, valve springs, lifters, seals, retainers). I am very mechanically inclined and have a fair bit of experience.

I've looked into the High Energy 268H from comp cams, but I feel that maybe my engine could perform well with a little higher? I know it is pretty much stock but the 268H description says its designed for street engines with stock manifolds, equipment, etc. while I have some bolt ons. I did find the Thumpr 279 which looks better, all though I know nothing about matching cams to intakes and heads and all that good stuff. The kit is "#K12-600-4".

Let me know what you guys think and I can really use ALL suggestions you might have! Thanks!


UPDATE: New quest on choosing aluminum heads starts on page 3.

 

Like the old 268 he cams. Decent idle make good torque works with a stock converter. Get a good exhaust, curve on the dist etc. Performer type intake will help some
Hard to say what you have without finding the casting # on the heads, have to assume its the low compression 350. A $30 borescope from Oreillys you can get a look at the piston top to better tell you what you have also before buying parts

 

I like the old school comp 268 cam also. The old school Isky 264 cam is another good cam for a low compression 350. Had that cam in my 76 L82 and it had tons of low and mid range. A friend has an 81 c3 with a 260 gm crate motor, 4 speed, 3.73 rear, headers with side exhaust, 600 edel. carb and performer intake. He had the 268 cam for awhile but wanted more lumpy idle but due to such low c r could not go bigger. We installed another old school cam, the crane 274ho6 218-218 450 lift on.a 106 las. It is an old circle track lift rules cam. It builds good cylinder pressure and comes up on the cam really quick and sounds bad a$$ out of the side pipes. I put the same cam in my carbed 84 c4 with auto trans and 3.07 rear and mild stall. Was a little rough at 600 rpm in gear but sounded great. You can still get an Elgin clone under part number e1785pm from competitionproducts.com for $100 or so including lifters. Of these 3 cams I would probably choose the Isky 264 214-214 450 lift on a108 lsa if you find you have a low c r . 441 heads I believe have 76 cc chambers but who knows what has been done to them. I took my 274 cam out when I installed the summit 152123 large valve cast iron 72cc heads($630) and went with another old school cam, the Isky z20 228-228 450 lift 108 lsa solid lifter cam which has similar idle to the comp 268 and isky 264 hydraulic cams.

 

change your heads and put that cam in .i would decide on what hp you need or want then build the motor that you want.

 

http://www.compperformancegroupstore...Code=K12-238-2
is tough to beat with your specs. If you can swing heads and a cam that would be huge. A full exhaust and stock heads need a split duration cam. If you really want to go bigger and lumpier get a split duration cam, 268 on the intake, 108 LSA to keep cylinder pressure somewhat decent. Stay away from the thumper cams. They are junk.
http://www.compcams.com/v002/Pages/387/XE262H-10.aspx If your willing to adjust lifters every once in a while do what GM did back in the day, Put a solid flat tappet in it, something like this ground on a 108 LSA. http://www.compperformancegroupstore...Code=K12-676-4
It will make more power period.

 

Thanks for the replies!
Alright, so I'll stay away from the thumper cams. I'm still reading up on the subject and trying to understand what all these numbers mean. My main concern would be choosing the right cam that'll benefit me the most in the 1/4 mile, would the xe262h be better than the xe268h then? In the future I'll upgrade to a higher stall torque converter when I do my 200-4r swap, so I'm not too worried about converters. I'll be ordering the cam and everything I need within the next couple of days, just trying to make sure I won't be throwing $3-400 bucks on a cam that'll make my low end worse and barely give me any improvement.

 

Oh, and I already have a mechanical advance curve kit in the distributor and up until now I've had my initial timing advanced way up just to fill in for that missing low end.... Main reason I want a full kit is because my current heads are leaking oil bad when I leave the car sitting. Perfect compression, 150psi on all cylinders but the valve seals are bad or not even there. A full kit gives me new springs and seals so I'll have a repair along with an upgrade. Hopefully I won't have to be wrenching too much when the first day of spring hits

 

If you are not replacing your converter you need to choose the right cam or it will not perform like you want.

for what you want if it were me I would find out what heads you have and if they are the stock ones replace them with the vortecs and a upgraded cam. keep the budget down the fun factor up.

 

The XE262H kit is the best choice for you now. The Solid 268 I linked will run a noticeably faster 1/4 mile and work great but you will have to machine down the tops of the guides on the future vortec heads or buy the upgrade heads from Scoggins Dickey because of the cam lift. It will bottom the retainers on the top of the stock vortec guides and seals but will work fine with your current heads. This is fairly simple and inexpensive at a good machine shop.

 

I will be replacing the converter within a couple months, that's why I want to get the cam and engine work done right now with the stock converter. For the winter while I'm in my garage without a lift I'm getting my engine work done and when spring hits I'll have the car at my school up on a lift to swap the th350 out for a 200-4r with any converter we decide I'll need for the cam. My th350 right now I believe has a 1800-2100 stall, but I'll be more then willing to go with a 2300+ converter with my new tranny.

The heads are 441 heads from I believe a 69-70. Intake valve size is 1.94 and exhaust is 1.50, 76cc combustion chambers. The "best" of the smog heads I guess, but far from great performance. I don't have money for new heads right now, so I'm going to replace the valve springs and seals on the 441s to run for this year.
Unless new heads with stock cam will give me more gains then new cam with stock heads? I can't do both at the same time, as I'm just not making that much money still being in high school. I will in the future, perhaps next fall or winter get new aluminum or vortec heads.

 

a good dirt track cam will give you torque ,lunati ,and isky cams have some dirt track grinds with 108 lsa .

 

Thank you 63mako!
Will the 268 work well with aftermarket aluminum heads then instead of vortecs in the future? by "work well" I mean will they fit without modification to the heads? I know the heads will have to match up for performance, I'll focus on that when I get there. I would believe that aftermarket heads like AFR and Edelbrock wouldn't have the same design as vortecs. I'd take the 268 if it means a faster quarter mile, and I'll be sure to get the right heads in the future.

 

Go with the Solid 268 ground on a 108 lsa http://www.compperformancegroupstore...Code=K12-676-4
You will have to order from Comp direct to get the 108 LSA (custom grind). Sounds like you enjoy tinkering with your car and looking for the most power, lope and 1/4 mile speed. This will give you all that along with that awesome solid lifter sound. These modern solids are tighter lash (.016) compared to the old (.030) and don't require the maintainance the old ones did.

 

Alright thanks again! I am almost 100% sure I'll go with the 268 cam. How often should I expect to have to make adjustments with a mechanical cam? Once a month or so? Maybe for reliability I'd be better off with a hydraulic flat tappet, not sure but I'll for sure go with one of the two. I love tinkering with my car but don't want to be constantly be pulling off the valve covers..

Also, will I immediately have to go with roller rockers when I swap cams or can I use the stock ones for a month and then switch to rollers? I'm getting mixed answers when searching online.

 

Use a good quality roller rocker bet you dont touch the lifters but 1 or 2x a yr. When the stocky style polylocks would get old youd see people having to adjust them more often think thats where the "having to do it all the time" came from. Have a fair sized solid roller it can go a year without checking. Not many miles done granted but still. I found one 1/2 thou off which isnt even enough to warrant a relash.

Love the way solids run and sound!

 

With the extra lift you will need at least long slot rockers. If you glue the gasket to the valve covers it goes easy on-off. Likely need to check lash after 1000 miles then every 5,000 or more with a modern tight lash cam. Polylocks are cheap and hold adjustment well.

 

If you don't use the vortec and go aftermarket aluminum, midgrade price, 180 CC port, 64CC, It will bump compression but the aluminum can run more static compression with the same cam so, yes it will work and you could buy bare heads, reuse your springs, new valves, reset up springs to save money on the upgrade. Can also reuse your intake and rockers then.

 

I put a Summit 1103 Cam in my stock 81 and I am quite pleased with it. Has a nice lopey sound to it. I was more interested in the sound of a lopey cam and have no idea of the power increase if any. I am sure there is some.

 

If you decide to run the 441 heads the Isky z20 will work with stock type springs. The z20 has 268-268 adv duration also. It comes on a 112 lsa these days but I had them grind mine on a 108 lsa for more low and midrange power. I am using comp poli locks and running a .020 cold lash. With the summit/dart 152123 heads I have all the power I need up to 5000 rpm. Old school works for me and isky has been making quality cams for many years and I have never had a failure.

 

Running a solid flat tappet with bigger lift with stock 40 year old hydraulic flat tappet springs is not how you want to save $100. Likely why it will only pull to 5000 RPM. Valvetrain control is critical for long valvetrain life and power midrange and up. Always use new recommended springs, properly setup when installing a new cam