need sbc buildup suggestions

[1979C10]

I'm trying to build a 350 to put in my truck. I've got a block, crank, heads, etc. from a 74 chevelle, a holley 750 vacuum secondaries, and a GM aluminum four barrel intake. I also have access to a set of 64cc camel humps and a Comp cams 260H. I want to know how much the stock crank and rods can take, what compression would work well, and any other suggestions to get me around 300+ horsepower.

[a1supersport]

Go with flat-top pistons and the camelbacks...your compression should be around 9 to 1, 9.5 to 1...depending on if you bore it out or not. That's about the max. compression you could run if you're going to use pump gas. 10 to 1 would be "pushing" it. The 260H is a good torque/smooth idling cam. Torque is good, especially if your vehicle is heavy...like your truck. But if you want horsepower, you may have to step it up to a 272H. But you'll scarifice your smooth idle, and some torque...which would sound good (lopey idle), but "off-the-line" power (torque) wouldn't be as good as the 260H. Just remember when you're choosing a cam, a lower number means your "power-band" will be down lower. Torque is what "slams" you into your seat off-the-line, horsepower is what pulls you through the finish line when your motor's screaming. I would stick with the 260H. I've tried it already...it's more enjoyable. Unless you want to "sound" impressive with a lopey idle. The stock crank and rods will be just fine, and 2 or 4 bolt mains are adequate. The only time I've seen main caps fail are after a crank or rod failure. 2 bolt mains, which is probably what you have, is more than adequate. The 750 vacuum secondary is more than adequate.

[greg_moreira]

Like stated above, your shortblock would be fine, and the compression ratio mentioned would be ideal as well. Getting a little massaging of the ports done wouldnt be too bad either. Just round off the roughness of the casting in the short side radius in the heads, have a good 3 angle valve job done and polish up the exhaust port and combustion chambers and youll be well on your way to having a set of heads that can make descent power. Dont get crazy with the port work, just a little mild cleaning up is all you need, plus if you open the ports up too much youll actually lose bottom end power due to a reduction in mixture velocity. Also, dont polish the intake ports cause you want the walls and floor of the port to be a little rough so it creates a nice boundary layer of semi turbulent air right up agains the walls, cause this will keep your mixture suspended in the port and moving better and prevent the fuel from puddling. Id put on a performer rpm intake too. A lot of people will tell you that a regular performer is better, but trust me, the rpm intake outperforms in ALL across the board when it comes to torque production and horsepower. If possible, Id actually put the 750 carb aside. A 600-650cfm carb will easily support 350 horsepower if its tuned right, and the smaller cfm rating will help to increase air velocity which equates to the same horsepower, but snappier throttle response and torque. It'll feel smoother and stronger during part throttle driving too. If its in the budget, a set of 1 5/8 long tube headers will be great too. You dont need to spend an arm and a leg on the headers. An inexpensive set of dynomax headers will do fine in comparison to manifolds. when its all said and done, you should be able to sqeeze about 365-375 ft lbs out of the motor and rougly 300-325 horsepower out of it depending on the quality of the heads. Good luck.