The old reliable 355 is now out of my car. It is being temporarily replaced by my brother's 454 that needs to be broken-in, tested and tuned. His Nova is apart in a thousand pieces so he asked if we could use my car to break in his engine. Can you say big block swap for the price of a tune-up, headers and some odds/ends? Of course I will... My brother has heard too many stories of body shops and the like abusing people's cars, so he doesn't want to take the car anywhere with the fresh BBC. Eventually my 355 will be used to get the Nova around for a while as the car gets upgrades starting from the rear of the car working foward ("no cost" swap for him, the Nova already had an SBC).

With the engine out, I might as well do a few cheap upgrades. Basically swapping head gaskets, gasket match heads/intake, replace cam, springs and maybe timing chain if necessary.

The basics of the engine are:
8.3:1CR cast-piston rebuilder engine. Low miles and runs well.
882 Heads with recent valvejob
Holley 300-36 intake (high-rise dual plane)
Holley 750VS
1 5/8 blackjack headers

Car will have:
3000rpm 10" converter
TH350
3.73 gear w/ 28" tire
CalTracs
69 Nova with power disc brakes, and power steering, no other options. No heater/ac stuff. I'm guessing under 3500 with 200lb driver?

Currently has an Comp 256/260 206/212 .420/.440 112LSA hyd baby cam that I think is way too weenie even for a stocker engine. Right now it runs 77mph in the 1/8th in my 3740lb Chevelle.

I want:
A solid flat tappet cam
Has to work the power brakes, other than that I don't care about street manners so long as it'll out perform the old cam on the strip. I don't mind adjusting valves once in a while, and welcome the solid-lifter sound, I'm willing to change the springs to provide room for more lift.

Freeway manners are of no concern and the engine will spend most of its time between the converter's stall speed and wherever the cam signs off.
I don't mind something that's a little on the edge of being too big.

The cams I'm looking at are:

Isky z20 268/268 228/228 .448/.448 112LSA
Isky z25 278/278 244/244 .480/.480 108LSA

Or a mix of the above with on 108 or 110LSA

Lunati 401A2 272/272 238/238 .485/.485
401A3 272/282 238/248 .485/.503

Probably try to get any of these on a 108LSA or 110LSA to keep some kind of cylinder pressure going on with the low CR.

What do you guys think?

I think you need heads, before you even THINK about a cam. I also think gasket matching in general, and crappy heads especially, is a total waste of perfectly good abrasive; because that's not where the restriction is.

I also think that any of those cams you mentioned will slow the car down, compared to what it is now. The increase in flow will produce less gain (again, that's not where the restriction is, so you can't improve overall performance by changing it, because it's not what's holding it back) than it will create loss in cylinder pressure. Net-net, it'll slow you down.

Go get a set of 416 casting 305 heads and have 1.94" intake valves put in them. You won't run with the Pro Stocks or anything, but it'll be a VAST improvement.

I think you need heads, before you even THINK about a cam. I also think gasket matching in general, and crappy heads especially, is a total waste of perfectly good abrasive; because that's not where the restriction is.

I also think that any of those cams you mentioned will slow the car down, compared to what it is now. The increase in flow will produce less gain (again, that's not where the restriction is, so you can't improve overall performance by changing it, because it's not what's holding it back) than it will create loss in cylinder pressure. Net-net, it'll slow you down.

Go get a set of 416 casting 305 heads and have 1.94" intake valves put in them. You won't run with the Pro Stocks or anything, but it'll be a VAST improvement.

I guess I should've clarified that down the road the engine will have something like a set of Brodix IK180 heads.

And I honestly think that something as small as the Isky z20 would run very well even with the crappy heads.

I agree with you that the heads are the biggest restriction, but I'd rather not spend any money that could be put towards REAL heads on another set of stock heads.

If enough people think the engines power output will drop even with the little solids, then I might not do it. Unless I decide to do it anyway like I did when I slapped the 750 on the car expecting it to slow down and the faster I let the secondaries open the quicker the car went. :D

I know of a couple of engines with smog heads and rebuilder shortblocks that MPH higher in other 68-72 Chevelles, all of them have very similar parts with the exception of the cams - they're all running 268 and 272 degree hydraulics.

What can I say, I like to experiment.

Hey slowpoke I have about the same engine as you in my daily driver. It's a fresh rebuilder type 350 that is .60 over. It's real fresh..It has those crappy heads, and Edy RPM a 650 dp, and a Crane Power Max, part number CRN-113821. I am very pleased with this cam. It's a hydraulic and I like it, you will too. It idles real tough at 600 rpm. Idling and not dying. The engine it replaced had the 327/350hp cam. The only difference is the old motor had the old cam and flattops. It had more compression than the current engine and it was still a dog. I'd say that this cam was a winner. It sounded better than the 350hp cam and kicked it's ass with less compression. The cam was not wore down when I took it apart so it was delivering it's full potential and the cylinders in each engine were great.
Both of these cams were ran in the 81 Camino with a 3000 stall and a 3.08 gear. Mismatched but true....
I have also ran a Cam Dynamics cam in an engine just like these,with 234/234 and .480 lift. . It had the 882 heads and 5 less cubes than the above motors. This was in a 74 Nova with a stock convertor, 3.08 gears and 600 Holley with the Weiand 8004 intake. Stock points too. I kicked a lot of ass in that car.
I would say that you just about can't go wrong with a 230 ish duration and a 470 something lift on a small Chevy. All the rest is just gravy........baby........Lol.

Enrique,

I thought that you were planning a big block of your own. Why drop dime on the small block?

Enrique,

I thought that you were planning a big block of your own. Why drop dime on the small block?

I am, but I guess I have a bit of an emotional attachment to this little mouse. I learned a lot by messing with the small block. I remember when it couldn't hardly break the 65mph mark on the 1/8th and I applied a lot of what I read to it and got it to 77mph. The engine is still so fresh that I have a hard time just getting rid of it, and I've always been curious about how it would perform with a few changes.

But I guess the 2-300 bucks I spend in a cam swap for it could be put to better use by adding them to the budget of what I'm going to spend on the BBC. I guess I should finally get the BBC project going, and then if it isn't done by the time my brother wants his back, I'll think about making some small changes to the small block before it finds its way back to the Chevelle.

I had a Comp Cams LT1 reproduction cam (solid lifter) in one of those GM $1200 replacement 350s like the old Targetmaster, total junk heads and maybe 8:1 compression. It ran suprisingly good and had alot of power for a 350. I always figured I must have degreed it wrong and got lucky or something because it should have run horribly. I think part of what made it ok was it was 114 lsa and it didnt have enormous lift.