[51 3600]

Originally Posted by dsraven

how about if you simply bend the edges of the cut inward so if the engine does move some- a mount fails or whatever-the manifold flange has a ramp to work with instead of a squared off hole.

Originally Posted by leegreen

Can you get the downpipe and donut on there? Looks tight to me, but hard to tell from photos.

I think I'd make that hole rounder & little larger then use torch and BFH to dimple the edges inwards a healthy amount. The dimple will keep the plate stiffer

I can get the down pipe on and planned on grinding the donut on one side. It’s somewhat smaller than the header flange to start.

Consensus says make the hole bigger. I like the idea of doing that then heating the edges and dimpling them. Because there’s so little space in which to work, using a torch and BFH would necessitate pulling the engine which I REALLY hate to do because I just put it back in. Arrrrgh!

Two questions: How big of a hole can I make without compromising the purpose of the boxing plate? Won’t most of the potential engine movement be in a vertical direction when the engine is under torque?