I guess you have a v-8
A lot of chevy trucks used a metal shield between the starter and the exhaust pipe. you could see if you could find one in a junk yard. You could use some exhaust wrap-header wrap. I don't really like it because it will cause painted or bare metal to rust a lot quicker.
Here is something you could make. Thaka piese of sheet metal cut to fit, then use a couple of u-bolts the size that will fit the pipe and bolt to pipe. Use nuts on both sides of the sheat metal so you can space the sheetmetal away from the pipe.
You could also get a larger (3"-4") pipe, split it and do ths same thing.
Richard