Don Terrill’s Speed-Talk

Looks like detonation to me.

GM 12555320 works great

The exhaust inlet to the turbo is so small I’m not sure how much more power you could get.

Manifold fit was fine. Block has not been decked, light cut only on the heads. Bolts line up perfectly. I used the stock replacement Fel Pro gaskets. Its ready to go out the door :) Glad I was not the only one rethinking this. I’m sure the stock gaskets will work fine. And they aren’t brittle like ...

Likely some of the pictures you’ve seen were mine BBC. I’ve installed my share of intake gaskets and never had a problem until the Felpro blue stripe gaskets. I will never use them again. I’m not a Felpro hater just the blue stripe gasket. I used their non high performance gasket to replace it and t...

Loctite epoxy weld

Too much air getting in from somewhere. Vacuum leak, throttle plates open, secondary throttle plates binding/not closing, vacuum ports open. Shouldn’t be that hard to find.

Always have - always will.

I ran a Straub Hydraulic roller in a 460” BBC 840 heads 3/8” valves factory 163 intake. Easily went 6500 which was my redline. A factory ‘70 LS6 had a 6500 redline. 6800 often might be pushing it but I’m not sure a 496 needs a lot of rpm to get the job done. I’m sure CamKing could spec a nice set up...

Building a 496 BBC with a little under 11.00 to 1 comp, ported 781 heads, 2.19 1.88 valves. It'll be mostly street some strip I'd like a cam that'll pull to 6800 or so. I've ran solid rollers on the street but figured I'd better go with a hyd roller. Either way they're dang expensive now. I'll have...

Building a 496 BBC with a little under 11.00 to 1 comp, ported 781 heads, 2.19 1.88 valves. It'll be mostly street some strip I'd like a cam that'll pull to 6800 or so. I've ran solid rollers on the street but figured I'd better go with a hyd roller. Either way they're dang expensive now. I'll have...

Almost always on a car that sounds terrible with it open or closed.

Viton made it over 10 years for me then sold it. Dry as a bone.

Why doesn’t he take it back?

Dow 111 silicone paste for o rings, etc.