[83GT]

Hey guys, this might sound kinda silly but I would like to get about 1000 more rpm's out of my 306. She tops out at 5500 right now and that's about it. If I were to make an assumption of how to increase this to 6500, I would have to get some stiffer valve springs. I am using the stock ones right now. Here's a little list of what I've got:

302 bored .040 over
TRW forged flat top pistons
Forged crank
Arias rods
Holley 190 fuel pump
Crane H-242 cam
Ported and polished 71-74 D20E heads (56.2cc)
Victor Jr. Intake
Heddman headers
Edelbrock 650 carb
Full MSD ignition
3.73 gears out back

Any ideas? Or am I just gonna end up with a grenade by trying this?

[Monkey Boy]

You've got the bottom end and the breathing capabilties to reach 6500 you just need the valvetrain to go with it.

[83GT]

Oops I forgot that I have Crane 1.6 roller rockers also.

[mstngjoe]

If you take a look at the specs for the H-242 you may see why you're done at 5500 with that combo.