Ok, here's a little update from my intake changeover this winter.
496ci, 12.5/1 comp, stock TFS heads, Comp roller 274/280 .683 lift, 107 CL(installed at 104), tunnel wedge, 1850 holleys
Made 665 hp at 6600, 621 ft/lb at 4400.
Installed adapter and Weiand tunnel ram.
Made 655 hp at 5800, 636 ft/lb at 4300 with 1850 Holleys.
It picked up torque down low and carried that torque up through the mid range, unlike the tunnelwedge which fell off as rpm increased. In the big part of the curve it was up 30 ft/lbs over the tunnelwedge until about 6000 rpm where it then started to match the tunnelwedge numbers. HP was up 15+ through that same part of the curve, but fell off over 6000 rpm to be -10 hp over the tunnelwedge at 6600 rpm.
It took quite a bit of tuning on the carbs to get them set up to run side saddle over backwards. The side to side A/F was way out in left field. After 6 gals of 112 and 5 hours of attempting to strip the bowl screws out of those 1850 we have it dialed in darn near perfect. I think we had 18 pulls on it total. The first pull was with the 1850's, did a quick jet change to fatten it up a touch and the power dropped off. We threw the 660's on it to just see what would happen, They were worse overall so we put the 1850's back on and continued to dial them in. My friend had a new pair of 750 HPs but never tried them due to trying to get fuel lines set up in a reasonable time frame. He didn't have fuel block for them yet(his build is still in pieces) so getting it all set up was going to take time that we really didn't have. This was a one day dyno thrash of sorts, so we just moved on. We played with timing, from 36-40* and it didn't care. We also played with valve lash from .016 to .022 and again not much change to speak of. The velocity stacks made negligible difference in power. It leaned it ever so slightly.
I think the biggest problem with it was the fact when I originally built this motor 2 yrs ago I was really concerned with transmission longevity(mainly first gear) and so I had the shop really hold back on overall power and RPM range. Since installing the Liberty Equalizer last winter I have NO qualms about making as much HP as I want. The tunnel ram now is conflicting slightly with the camshaft choice and not allowing it to pull up through like the tunnelwedge did. I'm not going to do anything about it currently.
I brought the motor home this evening. A few weeks ago I dropped my pressure ring off for a new heat shield install. I have that back and I put the clutch back together Saturday evening so it's all ready to put back in the car. It will run whatever it runs. I can see an 1/8 mile improvement with the increase in torque and HP but I'll be curious to see if it carries it through the 1/4 mile.
Overall I'm happy. Like anyone else I had high hopes to see a big "700" number but that will have to wait for another day and other changes. My friend is going to make me an aluminum "mailbox" style scoop to try out this year. If the velocity stacks don't work out well, I can try the scoop and see if the ram air effect will pick it up some. It went 10.28 first weekend out last year. In the heat it was in the 10.4 range. If diesel prices stay sane enough to be able to afford to go anyplace this year, I'll see what she will run.
Dyno video from FB:
https://fb.watch/bCwYlZNVxC/