Trickflow Valve springs & Scrub pattern

Alright, first let me say great job on the build. Family builds are the best, no amount of money can replace those good times. Looking at your build thread I think I’ve got your trap speed issue. The desk top dyno software is a great tool, but only as good as the info entered into it. Even then it will only get you close. That said, I looked at the specs on the camshaft 254 at .050 the recommended static compression ratio is the minimum. With that duration at .050 you really need to be 12.5:1 to 13:1, to take full advantage of the cam. Second issue is gear selection, 4.10 id say your coming through the traps at around 6000 rpm, with that tire. If your higher than that, it’s likely because of spinning down low. I watched the video, the car seamed to loose traction a bit off the line, and at the top end of the track had plenty left when you crossed the traps.

You did a great job gathering parts, the single plane manifold was a good choice for your target. Not worrying about street manners this would be my recommendation.

First if you intend to stay with that cam bump compression to 13:1, the DCR (Dynamic Compression Ratio) is some of the problem. With that cam and 11.8:1 your well in pump gas range, and leaving a lot on the table. You can degree the cam up and down to move where your torque comes in, if you installed the cam at center line, she should be coming in at around 3400 I’m thinking, so your stall at 3500 was a good choice for a street car, however if you were to retard the cam about 5 deg moving your torque curve up, and run a 4500-5000 stall you could keep the power band right in the sweet spot throughout the run. Of course it’s best to dyno the engine and find your peak torque and put the converter right there. Lastly gear, with that size tire and your target, not concerned about street ability, I would step it up to 4.88 in the rear, and get control over that launch. If these things were done your trap speed would increase as well as E/T drop.

Ok so that was to maximize the use of that cam with those heads. If you didn’t want to bump the compression, my opinion you would be much more happy in the 244-246 duration at .050 range. With those heads .600 lift is right on, from .600 to .700 the increase is minimal, so stay .600, when choosing a cam you can go up to 1.6 rockers if you cannot find a camshaft with the correct duration close to .600 lift to get you where you want to be. A custom cam grinder would be prefect for this situation and cost you just a little more than another shelf cam. Plus you save money keeping the 1.5 rockers. In this case the converter could stay the same but your peak RPM would come down a bit because of the reduction in cam duration. Going from 7400-7500 down to 6800-7000. Would suggest 4.56:1 gears for tire size and that combo.

Basically, with the car weight, the static compression ratio, cam you chose, converter and 4.10, with that tire. Your not making as much torque as you could with the engine, and the gear is leaving a lot on the table at the end of the 1/4 as far as getting the RPM up to offset the lack of efficiency.

Remember all Is for nothing if you cannot get spin on launch under control, if you spin at launch trap rpm will be higher and MPH lower. I like to mark the tire and slow motion camera the launch, so you can see wheel spin, adjust preload or ballast as needed.

Hope this helps, that’s a great build you should be proud of it...