Today was dyno day for the new 426W based engine. I used a 4.25 stroke with 7.10 rods and Diamond pistons. Heads are Trick Flow 240 heads and Dwayne came up with a 239/245 hyd roller cam. She made 613 hp at 5800 rpm and 631 ft-lbs at 4800 rpm. Torque was 522 at 3000 rpm where we started the pull and was 529 ft-lbs at 6000 rpm where we stopped the pull. So wall to wall torque. These numbers are about 50 ft-lbs and 40 hp better then the 512 engine which I had in the car so the car is picking up power even though the cam is a bit smaller. I assume that is because the Trick Flow heads are better than the ported RPM heads which the 512 had but it could also be the different intake manifold or the EFI system.

We did all of the dyno tests with a Holley Sniper setup. The Sniper is great to use on the dyno since I can sit in the control room and adjust the ignition timing as well as the jetting. We just hold the engine at a certain rpm and then tweak the timing and the fuel until it is working best and then move to the next point. It really is amazing what just a few degrees of timing will do at part throttle. At 2500 rpm we were able to reduce exhaust temp by 500 degrees by adding some timing. I've had cars in the past that would melt stuff under the hood while driving down the freeway and now I think I know why. Those cars had MSD billet distributors on them which didn't have any vacuum advance. We saw a big difference in exhaust gas temp between 35 degrees and 40 degrees of timing on the dyno at cruise speed. I'm tempted now to install a couple of EGT probes into my headers just to watch this in the car. I've been tuning for fuel consumption and manifold pressure at cruise but now I'm thinking I might also need to keep an eye on EGT.

I read somewhere that TTI headers will fit w small modification to the bellhousing and small starter.

That could be true for some cars but not mine. The engine in my car has been moved back and down in order to get the Doug Nash to fit in the tunnel so nothing fits off the rack.

I'm not sure if it's too late in your build to try this on the transmission or not. One trick is to rough up the cones on the gears so they get better traction in the synchro. Just use some 100 grit sandpaper by hand.