This is a T4 for an FC RX7 w/ haltech. This is my first time welding cast to stainless, i think it turned out well. This was pre heated and cooled submerged in sand.

 

hey, if you have a questin, just ask it. lol

 

well because this is cast steel i just used 309 rod. i dont have an exact temperature that the cast was heated to, but it was hot . and then i submerged it in a sand bucket and let it cool for like 4 hours. And i just started at one end and welded around it. and i actually just used a torch and slowly heated the entire thing up, it took some time but it worked. filler size was 1/16'' btw

 

looks good to me. asbestos works better than sand as well as an oven but ya, looks like she should hold just fine. keep an eye on it for a while or whatever, i can't see it being a problem if you welded it with 309L, i used to SMAW rail car trucks that were cast with 309L, just had to run the bead really hot and it worked fine, no special cooldown time or anything on those.