I am getting a set of 91 z28 l98 heads for dirt cheap to replace my swirl ports. I will probably do a mild valve job and port and polish to the heads.

I am getting a lt4 camshaft OR extreme energy 264 grind cam. Depending on what I do to the heads.

This will be on a 9.6:1 compression 350 roller motor. I have edelbrock TES headers with a 3'' hooker catback with no cat.

For induction I have a holley street dominator intake and a 670cfm holley street avenger carb. (may be going with a regular 600cfm holley)

would this put me close to 300hp?

 

I think you'll do better with the Comp cam than the GM one.

600 CFM is to small. The 670 would be a better choice. A slightly larger carb would probably be an even better choice.

300 HP is not unreasonable for that setup. With careful work to the heads, you may get more than that.