I already have Don's headers on my LG4 and clearance on a couple cylinders, especially #1 is tight to the primaries. Also, I tried Champion shorty spark plugs but there's a recess into the head at each plug and the hex pulls out of the socket since the socket is too large to follow spark plug into the recess and I can't finish torqueing the spark plug on all cylinders, namely again cylinder 1. This is with the stock 416 straight plug heads. The Vortec design exacerbates this problem by moving the spark even closer to the exhaust valve without angling the plug, which means it gets even closer to the header primaries. so my question is for those guys using Vortec heads with Dyno Don's headers, is there an even bigger interference problem than what I'm already experiencing? No, Vortecs aren't going on the LG4, I'm looking at swapping in an L31-R in the LG4's place. Do shorty spark plugs work with the Vortec heads? They seem to have a similar recess into the head at the plugs as my current 416's. Thanks for any help y'all can provide.

 

Get a 5/8 1/2" drive socket and weld a nut on the end of it.

That gives you plenty of room to turn it with a wrench.