Not sure on stock size. If you can get with no EGR, then great, otherwise, you will need a block off plate.

I guess another good question would be what size are the stock cylinders, no point having primaries bigger than them.

All the headers I've seen have the 1 3/4 or 1 5/8 size, so that should be good.

Depends..how much less are ones with or without? Not sure it'* an option.

Well with the ZZP ones, at least assume, they start with quality tubing and have quality welds, I want to modify a set to my standards, not try to build my own. . . . . yet

How are the 02 Sensors done in the SLP'*?

You say they are the best sealing and fitting, is this compared to some of the junk headers, or are they really better fitting and sealing than the ZZP stainless headers?

ZZP charges $10 to add the EGR, but I think I'm leaning towards taking Pat'* original advice and going with the SLP'* based on the fact that it sounds like they are the reliable way to go. The three piece should be easier to get in, and you guys obviously got them to seal up fine so. (Gotta keep Trent busy or he will start making weird videos again)

Have you guys heard of anyone using the ZZP headers, any problems, concerns? It sounds like there have been some bad headers going around but I havn't heard anything bad about the ZZP headers yet. Maybe they are one of the fabled good products?

Don't know about the ZZP headers, but some things your going to need to check for and deal with, the front motor mount will need to be modified. The trans dip stick will need to be a W body style, and where the O2 sensor is mounted. I know the TOGs are on the drivers side and the power steering lines are there. I had another bung installed on the passenger side.

Noted. Are you using both 02 bungs then? Or did you have to move it because it wouldn't fit with the power steering lines?

Assume nothing. Their Powerlogs in mild steel and stainless are known for cracking. Guys that weld for a living cringe when they see how it was welded. Those same guys have said the headers would never crack if the welds had been done properly. I'm not against ZZP here even though I'm sure it sounds it. There'* just too many screw ups from them that I've seen and when the customer has a problem, ZZP says it was installed wrong and suck up the cost. That'* a level of customer service I never want to sink low enough to accept.

The SLP'* are a slip fit. Therefore there'* no disruption in flow from exhaust donuts etc. The O2 bung is down in the main collector where it would see all cylinder exhaust gasses.

I'm assuming these are the headers you guys are talking about? SLP Headers

I do notice they say "When you purchase these headers, nothing will need to be beat on, ground down, relocated, inverted, cut off or welded." If this is true, that'* a big selling feature in its own.

That don't include the Bonneville.