I didn't want to post a cam thread since they seem so abundant, but I decided it wouldn't hurt to ask.

I've just about got my parts selected and I'm in the process of buying them.

My plan is to use the factory l48 block which was bored .030 over to smooth out the cylinder walls. I'm going to tap and grind the block to use late model roller lifters retainers and hold down. Using the factory crank from the l48 and breakaway rods I took from a 305. flat top pistons good for about 10-10.5:1 CR. GMPP Vortec heads upgraded with lt4 springs for .525 lift. Set of Crane full roller rockers. Also using serpentine belt system that I took of the same 305 as the rods.

As for the intake, I plan to buy a very cheap procomp vortec aluminum intake with an edelbrock 650cfm carb. I went with the cheapest intake I could find because I plan on getting an Edelbrock EFI system later on so I don't want to waste too much money on a carburated intake.

Right now It will be hooked up to the factory Turbo350C auto tranny but I plan to get the 6 speed conversion kit as soon as I can afford it.

This car will only see a track maybe a couple times a year. It is a street vehicle and as soon as I finish with all the major upgrade, like the engine, and tranny, It will definitely become my daily driver again.

I hope to get 400-450 horsepower. Of course more is never a bad thing,
however, being a street vehicle It needs to drive well on the street and I prefer mid to low end power, so I know the duration needs to be kept low.

I was originally looking at the ZZ4 cam, but decided it probably wouldn't give me the power I want. The cam I recently found and is my top choice at the moment is said to be an LT4 hot cam but is a bit more radical than the hot cam GMPP offers. It has .510/.520 lift with 1.5 rockers with 230/236 duration a .050 lift with 110 or 112 lobe centers available.

Does that sound like a good choice or does anyone have some other opinions and/or suggestions?

 

I can tell you two things about your project:

It is not wise in a performance motor to run the lift near the max rated spring lift. Because springs degrade with time and the more they work near their max lift the less time they last.

Off hand I don't know the CFM of your head flow. But the rule is the more head flow the less cam you need to make the same amount of power.

230 degrees is nice on a 355 ci More lift gets the heads flowing. I had my old 355's with high lifts using 1.6

 

Not clear from your syntax ... but a 305 crank will require lotsa balancing if used in typical 350 ... maybe you meant L48 crank ... unclear. You will see your predicted HI-compression ratio w/ thin shim gasket like fp 1094. Street car, driver, HI-comp, iron heads, street gas ... cam accordingly.

Instead of reworking old block for OE rollers ... Why not find an inexpensive late ('86-up) core 350 that needs boring? ... one that's ready for OE roller lifters. Then again, maybe you've already had the old block bored $.

 

sorry, I will rephrase that. I'm not using the 305 crank, just the rods.

and gkull, your opinion about not running with lift close to the maximum the heads can handle. That issue is solved because I am having to send my heads back because 2 of the exhaust valves were different than the rest. Since I'm going through the extra trouble I decided to opt for the next step up. Same heads but upgrade to allow up to .600 lift. That way I won't have to worry about failure like you mentioned, but also future proofing them incase I decide to increase the lift sometime down the road.