Welding Tips and Tricks

Hi there. Hobbyist tig welder.
I have a om613 exhaust manifold made of cast stainless however it has a t3 flange instead of a t4. I was wondering if its reliable to cut the t3 flange with a bandsaw and weld a stainless steel t4 ? Is it gonna be reliable? I cant really run a adapter because of space constraints.

i have no idea on how crack resistant the weld would be.

however i suspect its not going to make much difference. you need a LOT more clearance going by that pic.
if there is room sideways i would look at making a 45 degree or even 90 degree adaptor.
or relocate the alternator.

can you flip the manifold or relocate the alternator to a lower position?