I have one 496 base, that I have put Raylar cam in, and lifter set.
I need some recommendation for someone who can make me a file from base to raylar...

Also I would like to buy stiffer valve springs, and throttle body from HO..


Thank you for help..

Whipple can program the 555pcm. 496 mag and HO had the same valvesprings and throttlebody. The HO tb plate had a slightly larger air bleed hole.

Alot of 496 info......
Test ran the new Raylar goodies

thank You for reply, and good info about TB..

I know about valve springs from base and HO, but I think they are weak spot even on stock engine (maybe I heard wrong), so with raylar cams and lifters I was hoping tu run it till about 5400 rpm

Which Raylar cam? Did you do the rockers too? You'll probably get just as much from the rockers as the cam upgrade to make it worth your time.

If its the 203 its a little hotter than the HO cam. Maybe check with Raylar or Crane for something a little stiffer. I agree with you, they are painfully weak.
If its the 206 I am not sure I would run that in the stock heads or with a stock bottom end.

You can probably pull off a Whipple reprogram stage 1 or maybe stage 2 if you feel a little feisty.

Yep the stock springs are weak. 60lbs closed psi. 200lbs open on a good day. Pretty good track record though. I've never heard of a STOCK 496 8.1 with a broken valvespring. I used the 203 cam and installed Comp 911 springs, retainers, locks and rotator eliminators on the stock heads. With the Comp 911 spring kit. Heads milled .006". 1.865" IH 140lbs seat psi. Checked PTV clearance. .180" intake w/203 cam. Exhaust is way over .400"

You don't want to rev the 203 cam over 5100rpms with stock heads and intake. Nothing to be gained.