if i end up keeping these heads im wondering if it is worth to port these heads to get a bit more power out of my engine. if you can send me to an article i dont know the first thing about porting a head.

i ran a 12.9 @ 110mph the other day at the track.

350 .30 over
flat top pistons 4 valve reliefs
edelbrock rpm heads
edelbrock rpm cam
comp camp pro magnum 1.6 rocker arms
edelbrock rpm air gap intake
edelbrock 750 cfm carb
march underdrive pulleys

 

Based on the MPH from your track times, you're making the power that edelbrock says you will using their RPM combination. Based on the et there is a ton of room for chassis/ torque converter/traction improvement.
You should be running low 12's (12.1-12.2 @110mph) What are your 60ft times.

The edelbrock rpm heads are pretty good in stock form. They flow 232cfm@28" with good velocity.
They have a ton of potential and will flow a lot lot more when properly ported.
You will want a new cam with more valve lift to take advantage of the now increases airflow and rpm at high lift that porting gets you.
You may have noticed I post a lot about porting stock 305 heads for increased performance on a budget. The basics are the same. But.... the RPM heads ports have a good basic internal shape for good flow quality. Unlike a junk stock 305 head where what ever you do to remove metal from the port is bound to be a benefit. (its hard to screw them up) you do not want to just get in there and hog them out. You need to either get some one who has done professional porting and flow testing to show you what not to do, or get some of the good head preperation books available and absorb the knowledge.
I'd get an old stock head to practice on to get the hand control skill up. If you were to look at the shape of the rpm ports and try to make the stock ports the same or as simular as possible you'll gain the practice nessessary to move up to doing a good job on your RPM heads.
You do not need to make the ports huge. You'll be removing about 7 to 10 cc of metal from each port. The shape of the area just under the valve is critical. Don't just hog it out. It needs "shape" ( a funnel or venturii) there to help the air negotiate around the partially open valve edge and into the chamber. The bowl shape and valve job multi angles must work together) The guide boss needs to be trimmed and streamlined to split the air around it with an idea of rejoining the air again once past the guide boss. Look at a set of AFR heads in this critical area. You cannot make them exact as AFR's without adding metal (welding) but use them as a guide. The roof of the port should be made taller to about the size of a felpro 1205 gasket. The push rod pinch can be opened up a little. The floor basicly just needs smoothing. Do not lower the ramp in the floor. Just smooth and contour it and and side walls.
The chamber can be unshrouded some. Most people think that the area closest to the bore edge is critical. It's not. The area that is critial is the area within 5/8" of the spark plug. Again look at a AFR or vortec head and see where the chamber is contoured to manage and set up the airswirl into the chamber. This area is where the most of the intake air is headed for. Squirt water thru the open port using your garden hose and watch where the water goes. The port and chamber have to work together. These heads when ported properly have 260++cfm flow and will make way more than 500hp. If you can get them up to around 250cfm by your self at home you've done a good job.
The exhaust is basicly the same as porting any other SBC exhaust.
bowl area funnel shape,, guide boss contouring to create two flow paths around the guide boss. raise the roof and enlarge the port exit to header tube size but keep the squareish port shape. easy 190-210 cfm with a 1.60" valve.
With a good home porting and a new cam (get a real cam this time) You should be in the 114MPH area (475HP) With chassis, torque converter and tire upgrades your et should be in the high 11's @114.
I'd get a hyd roller cam or a solid flat tappet or street roller .500" to .560" lift with shortish 240 to 255 degree at .050" Do not buy a converter with less than 3500 stall. You'll probaly want to move up to a holley 750. A proform or holley "HP" carb body is nice. You'll have to decide for yourself if you want to move up to a Vic JR manifold or stay with the RPM.

What were your 60ft times?

 

best 60 foot i could get is 2.09

 

Should be in the 1.6 to 1.7 ish range. Everything you knock off the 60ft comes right off the ET. you have lots of MPH (horsepower) Need to give it some torque (cam LSA and intake C/L and header collectors) and traction (tires and converter). Was that open or closed exhaust? what tires? what converter?

 

hedman 1 5/8" long tubes, 2 s-bends, summit h-pipe, 2 moros spiral mufflers and turn downs. i have a built 700r4 with 3000 stall converter, 410 posi rearend on stock rearend. i ran with 17" TT II's on 255/40/17s

 

Would be likely be a whole different story with a set of drag radials.
www.mickeythompsontires.com

 

are these heads good for a blower? with flat tops and 64cc heads

 

You'd probably end up with too much compression to be blower-friendly with flat-tops and 64cc chambers.

 

would a set of 76cc heads be fine?

the block has been decked, and im running a felpro 1010 head gasket.

 

64cc heads on a standard bore 350 would put you about 10.2:1, assuming zero deck with 5cc valve reliefs. 76cc heads would give you about 9:1, which is maybe still a little high. A 12cc dish would put you down around 8.4:1.

 

A street true pump gas blower motor (6-71) should have a compression ratio of 7.5 to 8:1. So to use a 64cc head, you'd want a piston with a -30 cc dish volume. This will give you a 8:1 cr with a "0 decked block". If you want a 7.8:1 cr , just remove 4 cc from each combustion chamber (68cc)
To swap in a 30cc dished blower piston ( JE or Wiesco) should only require a cylinder honing, if your motor is still fresh. Slightly more piston and ring clearance is desirable with a supercharged motor.

The cheap and dirty way to build a 350ci blower motor (with off the shelf parts) is to use TRW L2441F-30 22cc dished forged pistons and larger chambered heads opened up (deshrouded) to 78cc.