I want to build a 498ci stroker based on a 454+.060. I have purchased a B+M 250 blower set up. What runner cc should I go with, I have two choises 320cc or 360cc in Procomp heads with 115cc chambers. Also any recomendations for cam selection and initial piston compression. This will be a twin engine set up in a heavy 1984 Formula 302

Try to keep it around 8.5:1 before you put on the blowers.

Head runner size really isn't going to matter much because you are using the blower.

I would go with the smaller size in case you decide to take the blowers offf later on and sell theboat without them. It will still reun good on the carb. The 360's would be way to big for that engine with or without the blower.

The stock Merc cam will be big enought for those engines also. Again becasue the blower is going to make the cam bigger. Also, if you take the blowers off, you will still have a pretty strong running engine.

Shoot for around 8 to 1 Static Comp ratio. You can always run more boost. I would go with the smaller runner heads. Get some flow numbers and then consult rmbuilder for a cam.

Yeah to what Griff says

I run 8.5:1 compression . You want the smaller runner heads hands down. Intake runner volume is very important to properly match to your combination. With a smaller supercharger the 320 runner will make alot more power than the 360. I run a 320 runner cylinder head on my 1000 HP package and they work great.

Thanx for the replys. The 320cc where $200 cheaper, an added bonus. Next I have to find rmbuilder or anyone else with knowledge for cam choise.

Scott at Dyno flow is pretty good at picking one out. I PM'd rmbuilder for one I am trying to build right now. Waiting to see what he has to say.

I can help with camshaft design. I rarely ever use catalog cams.

PM me, I have a couple different combinations I am working right now and could use some guidance.

Thanks, Jeff