I need to change my passenger side header gaskets on my 1970 GS. It’s formerly a GS350 that the previous owner swapped a nicely built 455 Stage 1 in Place of, with MT headers, and air conditioning. I’ve read on here that this can be a royal pain, and am wanting any tips you more experienced guys have that may assist me in doing it right... I’ve got Remflex gaskets already, and was considering buying a set of TA’s stainless 1112ss 12 Point header bolts. Are these hardened? I just don’t want to be fighting any future issues if possible... My plan was to replace the old ones with new, coated well with anti-seize. All my previous experience on Skylarks were on 350’s, without AC, so I’m guessing I’ll be using my entire foul language vocabulary and possibly creating some new words while trying to fix this...
Just prepare yourself to walk away a few times when it makes you mad.But,keep at it and it will get done..Not a fun job,but I'd rather do that than a heater core job..Have a couple ratchet wrenches handy as well..I try to remove the hardest bolts to get off first and even do the back ones from underneath the car.
The middle one under the center tube is the pain. If you are just replacing the gaskets, just disconnect the header at the flange, remove all the bolts except the center one and pull the header away from the head. Pull the gaskets out and slip the new one in. Slot the gasket center hole.
ARP offer 3/8 and 5/16 head bolts for BBC headers. The kit comes with 16 bolts so you have a couple to spare for future losses.
It's no prize, but honestly I'd rather do the passenger side than the driver's side. The steering shaft really gets in the way. The remflex gaskets are awesome, but you need to keep re-tightening for some time. so not over tighten, follow the directions and this will be the last time you mess with it. Good luck.
I think the 3/8 head header bolts i got from TA are 1in long and the 5/16 head bolts I sourced at Jegs were 3/4 long. I'm not sure how deep the threads are on fast iron heads. If you have clearance i would go with the 1in long ones though.
I think you're right...I looked at the thread length on some oem manifold bolts and they appeared to be longer than 3/4" long on the threaded portion. Looks like 1" are a safe bet...I'd rather not sell myself short on clamping force.
I had a friend that helped me decades ago on this and I literally had to buy extra bolts to give him to throw or power spike into the concrete every time he snapped lol
