Tig welding help on two different thicknesses

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Hi,I have been lurking around the forum for a while, what a  great wealth of knowledge here.  This is my first post.I am going to weld two different thickness mild steel together.  One is 1/8" and the other is 3/16"  What I am doing is welding in some motor mounts in my 1930 Model A, with a V8 flathead.The motor mount is 3/16" and the frame is 1/8".  I have a Lincoln Precision Tig 275.  What I am asking is what size tungsten should I use, 3/32" red 2% thoriated, what amp setting would I use, and what postflow?  I am going to tack the motor mounts in first to make sure everthing lines up then going to weld them in on the top and bottom sides.Please give me any tips and advice before starting this endeavor.Thank you in advanceNick
Reply:Scratch start?Are you using a remote amp controller?
Reply:Sorry should have included that. The precision tig 275 is HF (high frequency) so no scratch start, and I have remote amp controller (foot pedal)
Reply:I have a bit of advise, but not in the form of settings. If your using a stock A frame, be VERY careful welding on it. They are made from some of the most garbage steel I have ever seen, prone to hardening around the weld, and then cracking. Back in the days of "rodding" these frames, people found out that stick welding them just didnt last, yet O/A would since it pretty much prevented the hardening. Tig is going to do the same as stick, even to a worse degree. I would HEAVILY suggest making a bolt or rivet on mount rather than welding to the frame.
Reply:makoman,Thanks for the reply, I should have clarified that, this is a new perimeter frame new steel.  Those old A frame are for sure junk if you are going to do anything other than run that original 4 banger.Thanks Nick
Reply:Nick, Good to hear! Good Luck!-Aaron
Reply:3/32 tungsten is plenty good. Lanthinated or ceriated holds up better than thoriated, (but that will work also).I personally would set my amps @ 120 - 130 DCEN. Using the amptrol to control the heat and pool size.Post flow I generally keep set at 10 sec."SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:Keep in mind the heat will go where you point your tungsten, so you'll want to angle it a little more towards the thick piece of steel. X2 on papabear's settings.