I just had some thorley(sp?) headers installed on the GMC. I'd blown gaskets
several times the last year (I bought the GMC last August) and decided to
make the change. The instructions that came with the headers were very
specific on tightning the header bolts. Run the engine 20 minutes and
tighten hot, tighten after one day, again after a week , again after a
month, again in six then check yearly there after. I wish I'd known this
before because I'm sure that was the problem I'd had, the shop doing the
work never mentioned this.
I've also just installed Bilsteins all the way around and appreciated the
GMC specific instructions with the shocks. I definately need a larger floor
juck, the Sam's 2 1/2 ton doesn't do it. Luckily I've a couple of 12 ton
bottle jacks which worked well.
John
1977 Royale
GMC Tidewater Crabs
several times the last year (I bought the GMC last August) and decided to
make the change. The instructions that came with the headers were very
specific on tightning the header bolts. Run the engine 20 minutes and
tighten hot, tighten after one day, again after a week , again after a
month, again in six then check yearly there after. I wish I'd known this
before because I'm sure that was the problem I'd had, the shop doing the
work never mentioned this.
I've also just installed Bilsteins all the way around and appreciated the
GMC specific instructions with the shocks. I definately need a larger floor
juck, the Sam's 2 1/2 ton doesn't do it. Luckily I've a couple of 12 ton
bottle jacks which worked well.
John
1977 Royale
GMC Tidewater Crabs
