The biggest thing I’m guessing power is are we talking stripped with dyno headers or full marine trim with boat exhaust. Usually a very large difference. Mark at MER performance has proven in back to back dyno sessions runner length on NA builds can be as much as 30-40hp.

Stripped with dyno headers. I have CMI headers running full wet but that’s just too many variables to consider.

Older Sport headers.

YEs. Still short runner. NA wants longer runners variable to build but generally in the 30-32 inch range with id varying. This is also one of the reasons 525s came with sweeper headers to help get the power. Of course sweeper headers are too rich for my blood. Lol. Just know you’ll be leaving power on the table over a longer runner exhaust

That’s of no worry as it’s not a max power engine build and I’ll be perhaps +75hp over the stock ZZ502 that I built this off of. In fact, I’ll probably switch to manifolds when a nice set pops up and loose even a little more.

Another Coors light of your desired coldness!

Given that I cant find a dyno willing to dyno anything not built in their shop we may never know so I must accept the highest number as that is what pleases me. So far we are at one million HP!

The only dyno shop I could find was three hours away and almost $2k. Screw it - toss it in and send it!

First start up. The distribution hose fell off of one nipple of the headers hence zero water out of the SB exhaust, but otherwise ran like a champ.