67 big block timing chain cover
Are the timing chain covers for a 427/400 and a 427/435 the same or different? Same question on the timing tabs?
-
-
Re: 67 big block timing chain cover
Charles-----
The covers, themselves, were the same. However, the timing tabs were different. The L-68 engine used a 7" balancer and the L-71 used an 8" balancer, so the timing tabs were different and were welded on in slightly different locations to accommodate the differences in balancer OD.In Appreciation of John Hinckley -
Re: 67 big block timing chain cover
Joe you have been a great help in the past and I do not doubt your word. Look at page 114 of the 67 judging manual it says all big block balancers are 8". Is it just wrong? Do you have the GM part number for the correct 7" balancer, timing cover and timing tab? Also any thoughts on the best and quickest supplier? Also could you give me the correct part number for the 400 flywheel? I found everything else I need and trying to finish a rebuild.Comment
-
Re: 67 big block timing chain cover
Charles-----
If the 1967 JG says that all 1967 big blocks used 8" balancers, then the JG is incorrect. 1966-69 L-36 and L-68 big blocks used balancer GM #3860008. This is a 7" balancer (actually, 7-1/16" by measurement). It is GM-discontinued but available in replacement and reproduction markets.
The original timing cover for your application was GM #3882820. This cover included a welded-on timing tab and this tab was never available separately from GM. The GM #3882820 cover is a non-dowel pin type cover. It was discontinued in May, 1969 and replaced by the first dowel-pin type cover GM #3935443, with dowel pin holes unused for your application. That cover was discontinued in February, 1972 and replaced by GM #3975941 and that cover was replaced in December, 1973 by GM #330850. The latter cover is still available but its configuration differs considerably from that originally used for your application. It is 100% functional, though, and must be used with the bolt-on style timing pointer.
The original flywheel for your application was GM PART #3889694 and of CASTING number 3789733. This flywheel was discontinued YEARS ago and replaced several times. The current flywheel is GM PART #3991469 and it's still available. It's very close to the original in configuration and will work perfectly. No one will ever know the difference.In Appreciation of John HinckleyComment
-
Re: 67 big block timing chain cover
Anybody making a reproduction timing cover and tab that will pass NCRS judging or anyone selling originals at a fair price?Comment
-
Re: 67 big block timing chain cover
Charles-----
I don't know of any reproductions. However, used examples are pretty common, especially for the one you're after. All 1966-67 big blocks with hydraulic lifters used in passenger cars, Chevelles, and trucks also used the cover you need. There were a LOT of these built. The cover for 8" balancer applications is a lot harder to find because there were many fewer of them built.
You should be able to find what you need on eBay and enough of them that the prices shouldn't be too steep.In Appreciation of John HinckleyComment
-
Re: 67 big block timing chain cover
Thanks Joe.Comment
-
Re: 67 big block timing chain cover
7 inch timing tab is squared 400hp, 8 inch timing tab is tapered 435hp Also there is the no dowel situation. I don't remember the early or late version had a dowel hole or not. So basically the timing cover reflects the year used. Also the nut at the bottom of the timing cover. I think 65 66 had them and 67's didn't Some one can correct me on that.
Thanks, GrantComment
-
Re: 67 big block timing chain cover
Grant-----
1967 big blocks did not have dowel pins and the original covers had no provisions for them. The first dowel pin style blocks were used for later 1968 applications.
1967 did not use the bolt to retain the oil pan to the timing cover. However, I don't know if the GM #3882880 timing cover had the weld nut, or not.In Appreciation of John HinckleyComment
-
Re: 67 big block timing chain cover
Joe. Are there any numbers on the cover and balancer I have someone who may have them but how does he tell they are the correct ones?Comment
-
Re: 67 big block timing chain cover
Charles,
Having just gone through this recently, I will mention what I believe to be true.
There are no externally visible part numbers or stampings.
For 1967, there should not be any dowel holes. There should be a hole at the 6 o'clock position. This hole may or may not contain a weld-nut on the upper side of the flange. The weld nut seems random in that some late 67 cars seem to have them, others, even early cars, do not. Personally I would not obsess about this feature as it is not easy to observe when installed.
As Grant noted, the 7" tab has a squared edge while the 8" model has a 45* angle on one edge.
As far as I know, no vendor has an acceptable reproduction. I believe some vendors may have used originals available. The $65 from LICS, Paragon, and others is a later model cover that is functionally interchangeable but would have the dowel holes, a different shaped indentation on the front top (behind the cam gear), and possibly an incorrect tab.
As Joe noted, original 7" variants are pretty common and reasonably priced if you are patient, as this same cover was used on both 396 and 427 applications 65 - 67. The 8" is much more difficult to find, however it is possible to remove the timing tab from a 7" cover and attach a repro 8" tab to it.
Good luck.
JoelComment
-
Re: 67 big block timing chain cover
Charles-----
As Joel has mentioned, there are no identifying numbers on the timing cover. Just another one of the parts that GM should have identified with a stamping but didn't.
However, SOMETIMES the balancers will have a stamping on the face of the balancer hub section which is a 4 digit derivative of the part number. In this case, it would be "0008".In Appreciation of John HinckleyComment
-
Re: 67 big block timing chain cover
In looking at this thread, I found that I now have a question. Where are the dowels holes located on the cover? I just looked at another recent thread where a picture of a 65-66 timing cover was posted and noticed that there are a total of 10 holes drilled on the flange face through which bolts go to attach it to the block. I have seen examples where there are two more holes drilled (for a total of 12) - are these the dowel holes you're referring to? Would anyone have a picture of a late '66 timing chain cover that would have been on a Jan. '67 car? Note that this total of holes does not include the hole at the 6 o'clock position.....
Thanks for your help!
BobComment
Comment