Pman...you can bump up your power pretty good with heads and a bit more squeeze. here are some of my 351W combos the past ten years.
Here's a dyno sheet with my 351W comparing both a Stealth and V-jr intake.
This set up is a rebuilt FMS 385/351W with 11:1 forged Ross pistons, .576L roller cam, TEA ported Brodix 58cc milled , 190 cc runner heads. With the old flat tappet cam and GT40X heads ported, milled to 11.25:1 the motor made 376rwhp. After the rebuild and roller cam it made 386rwhp. A budget route for you might be AFR 185's milled to 58cc's for 11:1 and I bet you'd make 400 to the tire.
www.totalengineairflow.com makes the ported 190cc Brodix ST5.0 heads with 2.02 vales that flows 300 @ .6L for which I paid around $1900 minus rockers. The gain going to the Brodix heads from fully ported GT40X heads despite lessening compression .25 (58cc vs. 56cc's) was 419-386 or
a gain of 33RWHP. Just porting the GT40X heads on the stock 385/351W netted a 43rwhp gain from stock 334rw to 376RWHP . The TQ factor is not as high as the HP with these milder set ups which still does allow for foot control in 1st/2nd gears. Again...these were my preferences and experinces. I hope this helps as you consider mods to your 385/351W.
Except for my required rebuild due to a faulty BG carb, much of this can be done leaning over your hood. Figure 385-400 to the tire with good heads and 2 more points of squeeze (93 octane all that is required). If you want to run with the bigger dogs add a 100 shot for 3rd/4th gears. A couple of us did these 351W mods and have dynoed 485-500 RW spraying on the dyno. You're talking about 4 grand for all but it's only a few days of work in the garage.