Can I weld the plenum plate to the plenum? Instead of gaskets. Seems like a good idea to me cause it won't ever leak if welded properly

 

I know that several people have asked that, but don't know if anyone has eve done it. I would be concened that plat and cast expand and contract at different rates, but I am just guessing.

 

Sure, anything can be welded. The question is whether the weld will hold.

Really, how do get such a sound weld on this configuration. To add to gdstock's correct input, consider what is involved with welding Aluminum. TIG welder, which is with Gas. Now take that and understand where the weld will be in conjunction with getting gas to it for protection. Sure you will have the bottom with easy access, but you'd also need to provide gas to the plenum itself to ensure full protection of the weld. You know because of the gap b/t the plate and intake. So a good welder shop would have to backfill the plenum with gas as well as at the torch.

Its just not feasible, well only to a welder that has nothing to do and has the means to do it in addition to the skills of understanding CAST and Plate material. Now, this all assumes a sound weld all the way around. Chances of that are not 100%. There will be grind outs b/c of lack of penetration, slag, and inclusions to name a few.