The best are 3/8" heads with around 1" long threads. That is what I use now. I have tried 12pt, allen, and stud, none of those work. The 7/16" heads work 2nd best. Got to be at least an inch long thread as well. The way you put the headers on to get the bolts straight (gotta have the long bolts): *Put the header against the head without the gasket. Your gaskets should have the end two bolt holes open on the bottom so you can slip them in later. If your gasket is not like this, cut it so it is. *Put the first and last header bolts in for only about 2 threads. Just far enough to hold the header up without pulling out the first thread. *Drop in the header gasket. *Now, your header is up, but still quite a bit off the head, and the gasket is in place. *Start all of the rest of the header bolts. Again, only a thread or two. This leaves the header flange off the head so the bolts can be installed in the tight spots without having to force or fight threads while doing so. The header also has plenty of room to wobble, tilt, rotate slightly... Gives you plenty of play to get the bolts in tight spots. *Now all is left to do is tighten all the bolts down. DO NOT TIGHTEN ONE BY ONE! Instead, tighten them each a few threads, then go to the next. Repeat over and over until all have been turned in a few threads, then start over. Turn all 8 in a few threads at a time until all 8 bottom out and are tightenend at the same time. This keeps the header tubes from running into bolt heads prematurely as they all go in gradually and evenly. *Heat cycle and retighten. Dave
YEAH...Now throw a 1/4" spacer into the mix...makes it a bit more fun. On top of the fact that the 1" threaded bolts won't go in straight enough to line up with the head due to the curve of the tubes. I got the tubes pounded out so the bolts will straighten out within 1/4" of entering the flange, but now I cannot get the header back into place. I have given up for the day...my arms are bruised from banging on the brake master cylinder, and I am pooped. I am on my 3rd mixed drink thinking about why I cannot get the header back in. I can solve the rubik's cube in under 2 minutes, but cannot figure out how to get the header onto the engine around the power steering junk and bell housing...
Hey, who's putting a 1/4" spacer in there?!? If you are, then you have made things that much harder. I would trim the bottom out of the 2 end bolt holes, just like the gasket. You could even slot the bottom of every hole for that matter where a spacer is concerned. Pic of the gasket attached. Another trick was used by header makers in the past. They 'elongated' the bolt holes at a 45* angle when they were behind a pipe. You could do this to your header, slot the spacer, and use end slotted gaskets, and might have a shot. Attached is a sample of the bolt hole variation used on some SBF headers. It's hard to explain, so a jpeg might say 1000 keystrokes. Dave Edit: I changed my example pic, I think I did not orient the elongation correctly.
Dave, those are the same gaskets I am using. I notched out the rear hole to form a hook so that I could bolt up the front one (easy to do) then slide the spacer down over the rear one. Still had a problem with getting the bolts in, which is why I pounded out the rear of the tubes. Once I figure out how to get the header back in then I should be able to bolt it all up really easy-like...
Another trick is to make a cut in the flange next to each tube, effectively seperating each pipe so that it is independent of it's neighbor. This will help decrease the chance of leaks because each pipe will be able to seat against the head without the flange holding it back.
I had a friend do this and he had more trouble cause the tubes seemed to want to go there own way individualy. I thought the same as you Sam, but seeing what he was fighting...I might think about maybe only cutting into two sections each side...
OK, for those keeping up with this SAGA!!! Before you ever install ANY headers...do a little pounding on the inside of the tube. If you cannot get a 1" long bolt, or whatever bolt you are using, started straight into the hole, pound it until you can! After spending 5-6 hours just trying to get the one rear bolt in, then finally taking the header out and pounding some space into them, it took me less than 5 minutes to get ALL of the bolts started. It has never been this easy. This is the best/most efficient mod I have ever done to this car other than notching the shock towers. Highly recommended
why crimp the tube as it leaves the port without finding out if its necessary? at least find out if you need to dimple them first. you seem to have a unique situation with your 1/4 spacers. most of us get our headers on with a little finagleing and some patience, without dimples. i said most, not all. yeah, sure, i'll buy those 1 3/4 headers & then dimple it down to 1 5/8 where it exits the port. just my .02 cant help wondering how different the previous advice would have been if you had mentioned the 1/4 spacers in the beginning.
I thought I mentioned them, but now that I look back, I guess I didn't. I have been talking about it on another thread and assumed I had mentioned it here. sorry You are right though. The smaller bolts fit much easier, but even then, I had two where the points of the top of the bolt head were nicking the tube as it went around, and had almost put a hole in them. So something would eventually have had to be done to keep a hole from ocurring. Now, in the process of putting the header back in, I knocked the Hooker badge off. Guess what...they are riveted in so I now have two small holes I need to tack weld up... If it is not one thing, it is always another
I know I'm no help, but this might make someone feel better. I HATE HEADERS! But we all love speed so what you gonna do? Terry
I agree. Headers look cool, and may be neat in other cars (without shock towers, and with more clearance from the block). But in our Mavs, they are a b1tc#!!! Good thing, with my experience, at least, is once I get them all on and tight, I never have to worry about them again for quite a while (new plugs, wires, etc.).
Except for needing the spacer, the issue isn't the heads...this time. I was having bolt rubbing issues with these headers BEFORE I used the spacer. But only on two tubes, with the spacer, I had issues on all 4 tubes. I will buy decent aluminum heads, when I rebuild. These Ps really are GREAT flowing heads, for iron, but they are difficult to work with, to say the least. Well, I just got back from a fairly long highway drive and it ran great. Didn't want to start, as it hadn't run in over a month. I still have some kind of miss/hesitation, something electrical, I assume. But the new radiator kept at 165 in town (too cool, but the weather is cooler today so I will let it slide). Highway at 3300 rpm for about 30 miles and it eventually worked up to 180 degrees, maybe 182 at one point. When I slowed down back in town, it cooled to 175 and held right there...Starting another thread re: the hesitation/miss.
ShadowMaster that was just mean. But it was soooo true! Sometimes the truth really does hurt. Sorry Scott. Terry
