Ignition troubles: NOPE!
Fuel problems: NOPE!
RFI: NOPE!
electronics: NOPE
Intake/carb problem: NOPE!

Built a little 355 from stuff laying around and yanked the 383. To make a LONG LONG story short... with the same ignition system from the 383 (right down to the used plugs), the same carb and intake I tried a few weeks ago,, the little 355 with a set of box stock RPM heads, Comp 305H cam, Vic Jr intake, a Prosystems center squirter carb, a questionable used bore with a touch hone, TRW L2304F pistons (for 9.6:1 compression) and a mix of 1-2 gallons of left over C-12 and 3-4 gallons of pump 92 took it to 7400rpm before valve float.
So,, it's final. Something is wounded in the 383, but so far during teardown everything appears fairly normal. Have the heads off and the cam / lifters out but nothing is jumping up and screaming "Here I am", the investigation continues http://www.nastyz28.com/ubb/frown.gif

Oh,,, Engine / Drag analyzer predicted 11.44 @ 118 and nearly 460 horse in 4000' air. OUT OF A BOX STOCK SET OF RPM'S,, who are they kidding!!!. The package missed the mark a little. 11.57 @ 116.3 on a very loose track. <ROTFLMAO> I wouldn't have believed it if I wasn't sitting here looking at a handfull of time slips from Friday night. Took a few passes to find what she liked but at 7200 she is singing a song I had almost forgotten.

It's official,,, the car is NOT posessed!!!!

Gotta be the heads man....especially after all this.

Guess I gotta build be up a 'Marv beater' small block http://www.nastyz28.com/ubb/wink.gif

Well....Im glad you figured it out.

But Im mortified by your slapped together 355 kicking the CRAP out of my time at roughly the same Alt.......Jerk.

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72SS 406 350T(4200 stall) 9INCH/411 2890 pounds (and dropping)
http://home.att.net/~dwwest/index.html

I always found the dd to be off by a .1 or so and the mph was usually high but it's pretty close.
As for the car I'm glad to hear it's not that but am still quite curious to find out what it was.I know you've been through it several times but it sure sounds like a bad spring or something related.Let us know when you find out.
BTW that must seem like a pretty mellow ride after the wild launches you were use too?

Wade,, I'm sorry <grin>. Do keep in mind that was density altitude. We had 100 degree temps and a thunderstorm off in the distance. Our track is 1300'. I'm sure up there in the ozone on a warm day your air is,, well like racing on Pluto! Makes a HUGE difference.

I spent all day mapping every lobe of the 383's cam. Checking centerline, 0.050" opening and closing events, peak lift, base circle,,, everything on every lobe on the cam (all stinking day with a degree wheel and dial indicator). The cam is now also eliminated as contributing to the problem. Did find some oddities with the lifters tho. The rollers are all uniform diameter but I found the lifter body is spreading at the axle centerline. Some of them are as much as 0.0015" larger diameter than the lifter body and snug in the block. A new one is 0.0015 smaller than the lifter diameter <shrug> That portion of the lifter doesn't get into the lifter bore even at full lift but still investigating what is going on there.

The heads are sitting on the bench untouched. No visible problems other than darkened intake ports. Consensus is we are most likely getting exhaust into the intake or burning the fresh fuel/air on it's way down the runner. I'll get to the heads, but just making sure everything below the deck is as it should be first.

Cragger with the "ice racing" they call Firebird Friday Night the unpreped track still keeps things 'exciting'! It's amazing how more power drives the suspension to the track. Besides,,, I was so excited to see 7300+ I didn't even notice how slow 116 is. Next week is a team race and on a prepped track and either it will hook up and the motor will bog on the line and loose ET, or it will get darn close to the predicted 11.4's. Doesn't matter,,, if I can just find enough consistancy to go a few rounds I'll be a happy camper. This coming race is a National Dragster Challenge. Would have been nice to have a proven package and a shot at taking home one of those Wally's http://www.nastyz28.com/ubb/frown.gif

Have you inspected the needle bearing on the roller lifters?
How about the ability to compress the lifter under load (like a hyd).
I have heard stories of Solid-rollers breaking internally and kind of collapseing under load.
That could certainly reek havoc on the engine dynamics at speed...
If I remember you were having problems at 6200RPM+. That just happens to be the RPM where all hyd-lifters begin having bad things happen. I wonder if the solid-lifter had collapsed it could be taking on oil and acting like a hyd???
Just throwing out odd possiabilies since all the conventional approaches seem to have failed.

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1971 Camaro
350 / M21 4spd
12" brakes
16x10" Wheels
Autocross competitive
'83 VW GTI FSP for daily driver
Sales / Tech - The Speed Merchant, San Jose, CA
1-800-994-0930
http://www.speedmerchant.com/

Marv old man. http://www.nastyz28.com/ubb/biggrin.gif
What you mention about "blacked out" intake channels caught my eye.
So what you´re saying is that you get some sort of reversion?
I mean...that could basically be anything from exhaust not lining up to pulsing.
Engine sound "funny" when at WOT in any way?