Well I can tell you from a VERY personal perspective from last weekend...sit down and relax, this will take a moment...so last weekend I decided to break the engine in on my 68 GTX, 440, Eddy heads. I have coated TTI headers on the way, VERY specifically they say DO NOT break in a new engine on these headers or it will ruin the coating. OK. no problem I have a set of old hookers hanging in the rafters, I'll just throw those on for the break-in period...ahhh, not so much there buddy, old hookers wont fit eddy's, crap, can't even get the spark plugs in. Ok, looks like we're going to use the manifolds, built stub exhaust pipes, hang some glass packs on it to keep the noise down to where I can here the engine during break-in, sweet, good to go. Yes the plug boots on MSD 8.8 wires are tight, the number 8 does not touch but it has maybe .100 to .200 clearance, the number six however has about half of that...it is real close to touching. During my cam break-in...about half way through it, the number 6 plug wire boot caught on fire
, had to put it out with a water gun from my bar-b-que pit operation, number 8 was beginning to smoke when I finished. Yes, they are REAL close to the manifold...your results may vary...