505 stroker fresh off the dyno - Power seems low? Thoughs?

Those springs may be your problem.

Last year we took my 72 Duster to the track

408
Trickflow 190
11.2 compression
Howard Solid 600/615 254/260@050 108 in at 103.5
Strip Dominator
800cfm DP
727/3500 4.10 / 28

I am pretty sure the springs are the same as you got on the big block heads. They are rated at 120 on the seat and a pac spring isntalled at 1.9.


It only did 113.5 in the 1/4. Something was definitely wrong..

After talking to my friend Mike we took off some springs and tested them. We tested a few at the install height and were only getting like 110 and you could see the scrub pattern on the tops of the valves had been moving around. The valves had been turning.

We started looking to try and find another spring that would work with that same install height and everything and ended up ordering Howards HRS-98632

Valve Spring Set Series:
 Max Effort





Style Of Spring:
 Dual
Outer Overall Diameter:
 1.500
Outer Inside Diameter:
 1.100
Inner Overall Diameter:
 1.100
Inner Inside Diameter:
 .816
Damper:
 No
Closed Pressure:
 145 @ 1.940
Open Pressure:
 422 @ 1.250
Rate:
 413
Max Lift:
 .780
Coil Bind:
 1.100


This ended up being a spring pressure of about 155 Seat Open 390/400 area.

We brought it to the track this year and the car did 118.5. We were not quite wide open we discovered the previous year but it wasn't by much.

I think your issue is those springs. I had wished I had bought the heads with the one size stronger spring.

The howard springs went right in though without anything else needed to be changed. Perfect for the 1.9 install height and everything. Went right in and they are not expensive. They are lik $140.

Howards Cams 98632 Howards Cams Performance Street/Strip Valve Springs | Summit Racing

I am also running there EDM oiling solid lifters. I would imagine when the spring breaks in a little the spring pressure will drop some.



The springs are TFS-16893. Installed pressure of 120lbs at 1.875, and open pressure of 394lbs at 1.175. These are the springs that trick flow sends with their flat tappet 240 heads. I spoke to Howard's cams yesterday to pick their brains about things, and he was a little concerned about the spring pressure. He said he generally doesn't like to see more than 360-370.

Anyway, he recommended getting the cranking pressure up in the 185 region, moving in two degree incriments until it gets there. I'll be ordering the stall converter today, then get that in and get the engine dropped in quick. At that point I'll pull the timing cover and check/adjust the cam timing so I can crank it over.

I plan on 30% street and 70% bracket with the car. Just taking the kids to school, a few local car shows and such.