I used a mr gasket fan for awhile with a perma cool probe. seemed to work ok. I just traded it to a guy with an early 50's plymouth he said it works good for him too.
BFG makes good ties I have radial TA's on my truck and had comp TA's on my car for awhile seem to do good in any kind of weather hook decent when heated properly
dude have you tried the hardware store?
sears harware or the big columbus hardware downt town should have what you want I cant tell dimensions from your pic but it looks like a 90 degree NPT fitting with a hose barb on the end gimme the sizes and I can get it by monday
the citgo and sunoco at hamilton and I-70 both carry race gas(the same guy owns both places) they have all grades of VP race fuels, turbo blue, cam2, citgo racing fuel,and nitromethane the "cheap" stuff goes for 3.65 per gallon
I would call dirty radiator on that one. at highway speeds you force more air through it. dies your fan come on? if it comes on get the rad boiled out.
jack up the back put it in neutral and turn the driveshaft by hand if the rear tires move the transfer case is done if they don't the ring and or pinon gears are trash I would take it to 4 wheel parts or trails west if the transfer case is messed up if its a rearend you can get one at a junkyard pretty cheap.
in your olds? anthony knows a guy lives out near buckeye lake does good work. I did the ones in my buick it really sucked. I recomend highly taking it to get it done. you can also try Josh at reynoldsburg sunoco he does real good work too.
I have a bandsaw but no metal cutting blades if you get a blade you can use it I have a die grinder with a cutoff wheel on it to they work pretty good you may also want to try a sawzall with a good fine tooth metal cutter on it HTH