Brain Fart. YES!! Doug Thorley's, made for Mavericks. Thanks for catching the error. I previously had a deal on some Hedman's that fell thru.
I have the some ones, you'll be happy!! Just watch the bolts that come with them, mine were too long and didn't suck the header up tight, and the gasket didn't last long. You'll have to take them off, to drop the engine in.
I got the 3/8" hex head Chevy/Ford header bolts from Summit but I think they're too short. Looks like they'll only catch a few threads with these thick flanges. Thanks for tip on the bolts supplied with the headers. Right now the headers are just loosely held with a couple of bolts. I'll test fit bolts before the engine goes in.
Did you get the bolts that came with the headers? You could take a 1/4" off of each of them, and they'll work fine. At one time, Thorley would replace the bolts that came with the early headers, but I don't know about now, I got mine when they first came out.
Yes, but wasn't planning on using them. I ordered the 3/8" hex headed bolts from Summit that members here had mentiond. Now I'm wondering if some washers on the too-long bolts that came with the headers might put the bolt heads in a better position to get a wrench on them. I'll check it out.
With your elevation I would start with the 64 jets and the power valve will probably need to be a 6.5 maybe even a 7.0. Generally the power valve number is roughly half of what the engine idle vaccuum is. If you have an automatic check vaccuum with it in drive or nutral with a 5 speed. The only other thing you have to worry about is the secondary spring. a lot of that depends on the way you drive also. for starters I would leave it alone and then determine later if you need a lighter one or a heavier one. Hope this helps get you going in the right direction. Also, if you start with the 64 jets you can run the engine that way for a 100 or so miles ( makes sure you are running brand new plugs) and then pull one out and take a picture of it and then I can help you gauge what direction you will need to go ( richer or leaner) and what jets to put in.
I am just glad I could I help. Let me know if there is anything else you are un sure of. And, dont hesitate to ask any and all questions.
