You could've done what's called 'gasket matching.' Lay your stock gasket on the flange for the plenum to head and the throttle body, trace, and make the transition smooth from where it mated to the head and t.b. you won't gain any h.p. or trq by what you did. You may of actually adversely effected it to tell you the truth because you created more of a possibility of turbulence where you couldn't polish or smooth in the middle of the runners. It would be negligible, but gasket matching would've benefitted more and you wouldn't have needed to cut it open and have to weld it shut. There are some good books and info out there on the subject. It has alot to do with fluid dynamics, seriously suggest doing some reading. I've been building motors for over 25 years so I have a little knowledge in this department.
That’s Badass man much respect for real I appreciate people that actually do it themselves cause honestly I don’t have the balls to do that to my manifold or any manifold honestly awesome 👏 😎 work came out great💯👌🏾🔥
Well at least you try your best with the tools that you have,but honestly when you have to do the welding back on,with all those gaps in the aluminum it's going to be a mess inside the plenum.
