360 TrueStreet Magnum Build
Sounds like this will be like the 380 hp crate engine, but less $$.
Will be watching.
Are you sure you weren't a fly on the dyno cell wall?
I was able to complete this build and do some preliminary testing. Suffice it to say I did not quite reach 380hp.
All testing was done with a 600 cfm QFT vac sec because it is reliable and the biggest carb I have under 950 cfm right now. Esso 91 was used because that is what I had in the tank. I am confident this will make as much power on 87 . At no time or timing setting was the engine hard to start or shut off.
I wound up with 371-374 hp @ 5100-5200 rpm on pull 4 through 9. I only pulled to 5500 rpm where it was down about 1-2 hp from peak. What is really nice is the 428 ft/lbs @ 3900 rpm. I started the testing at 3250 rpm where 423.8 ft/lbs was observed. Idle vaccum was a steady and smooth 15-16" @ 750-800 rpm. Total timing was wound up at 37-38 total likely due to the low compression and no real quench to speak of. A half inch spacer hurt power everywhere. I was hoping to see 380 hp show up but not without putting more time than I have into this build. I feel that a 750 dbl or even a 650 dbl would likely crest the 380 hp mark and then some. Manifold vacuum was registering 1.1-1.3" in the upper third of the pull indicating the carb is on the small side and presenting a restriction. It is extremely responsive-I pulled it once as low as 2500 where 376 ft/lbs was available.
All in all I am quite pleased. It has stock valvetrain except for the springs,stock replacement pistons, stock rods (ARP bolts), crankshaft, dual plane manifold, and mild Lunati hydro roller. It almost matches the output of a Mopar 380 hp 360 crate but with FAR better manners/driveability and on cheap fuel and likely a bunch cheaper to acquire as well. J.Rob
View attachment TSMagnumdynosheet.jpg
