68 BB Exh Washers / Joe?

[Tom B.]

Re: 68 BB Exh Washers / Joe?

Thanks Chuck. I'm thinking along the same lines as you. I need to go back a count up what I have of each variety first. I may get by with what I have for installing the built-in washer types on the outboards. Thanks for the tip on the lengths. Tom #24014

[Tom B.]

Re: 68 BB Exh Washers / Joe?

Thanks Chuck. I'm thinking along the same lines as you. I need to go back a count up what I have of each variety first. I may get by with what I have for installing the built-in washer types on the outboards. Thanks for the tip on the lengths. Tom #24014

[chester]

Re: 68 BB Exh Washers / Joe?

I put the manifolds on with out the washers, jgrice I believe posted a answer earlier that there were no washers, but maybe some bolts that had built in washers, i'll check with him. jc Any additional info would much appriciated.

Did we stump the Shark?????

[chester]

Re: 68 BB Exh Washers / Joe?

I put the manifolds on with out the washers, jgrice I believe posted a answer earlier that there were no washers, but maybe some bolts that had built in washers, i'll check with him. jc Any additional info would much appriciated.

Did we stump the Shark?????

[Tom B.]

Re: 68 BB Exh Washers / Joe?

chester,

Too much to back-track with but I'm glad you didn't use the washers. You're on the right track now. This would be a good one for the new and revised 68-69 TM that you're thinking of publishing. Be sure to list me as a resource. Thanks. Tom #24014

[Tom B.]

Re: 68 BB Exh Washers / Joe?

chester,

Too much to back-track with but I'm glad you didn't use the washers. You're on the right track now. This would be a good one for the new and revised 68-69 TM that you're thinking of publishing. Be sure to list me as a resource. Thanks. Tom #24014

[Rolf Krueger]

Re: 68 BB Exh Washers / Joe?

1. Many years ago, I had a discussion with several Chevrolet powerplant engineers about the 454 CID engine. One of the things that I learned was that the change to the flange head exhuast manifold bolt in the outboard positions was part of the engineering release package for the production versions of the 454 CID engine for Model Year 1970 production. This release would have been made early in Calendar Year 1969. It is possible that some of the flange head bolts may have been installed on late MY 1969 engines, but I doubt that any made it on MY 1968 engines. Note that as soon as the MY 1970 release was made, this flange head bolt also became the service replacement item for maintenance in the field of earlier engines.

2. The hex head grade 8 bolt for this application is P/N 3736035, which is a 3/8-16 thread and 1 19/64 long. The flange head bolt is P/N 3909821, which is a 3/8-16 thread by 1 3/16 long.

[Rolf Krueger]

Re: 68 BB Exh Washers / Joe?

1. Many years ago, I had a discussion with several Chevrolet powerplant engineers about the 454 CID engine. One of the things that I learned was that the change to the flange head exhuast manifold bolt in the outboard positions was part of the engineering release package for the production versions of the 454 CID engine for Model Year 1970 production. This release would have been made early in Calendar Year 1969. It is possible that some of the flange head bolts may have been installed on late MY 1969 engines, but I doubt that any made it on MY 1968 engines. Note that as soon as the MY 1970 release was made, this flange head bolt also became the service replacement item for maintenance in the field of earlier engines.

2. The hex head grade 8 bolt for this application is P/N 3736035, which is a 3/8-16 thread and 1 19/64 long. The flange head bolt is P/N 3909821, which is a 3/8-16 thread by 1 3/16 long.

[Tom B.]

Re: 68 BB Exh Washers / Joe?

Thanks once more Rolf. I had been getting the feeling I was chasing my tail on this one. It sounds to me like the flange head bolt found it's way to 68 by replacement. I do plan to still make use of what I have (a mixture) but your info gives me a heck of a lot better idea of what was "more than likely" correct. Thanks again. Tom #24014

[Tom B.]

Re: 68 BB Exh Washers / Joe?

Thanks once more Rolf. I had been getting the feeling I was chasing my tail on this one. It sounds to me like the flange head bolt found it's way to 68 by replacement. I do plan to still make use of what I have (a mixture) but your info gives me a heck of a lot better idea of what was "more than likely" correct. Thanks again. Tom #24014

[chester]

Re: 68 BB Exh Washers / Joe?

I mail them and let them know. jc

[chester]

Re: 68 BB Exh Washers / Joe?

I mail them and let them know. jc