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Joe, What are the part #'s motor mounts for my 69 L-36 ? Will 3990918 which was superceeded to 3962748 work? And is the new GM stock the same appearing as older stock?
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Re: Question for Joe Lucia *NM*
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Re: Question for Joe Lucia
Brad,
Search back about a month or so with Joe's name AND my name and you will find a ton of info on the 69 mounts. We had a long thread on these mounts so you might find the info you are looking for in there.
GregComment
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Re: Question for Joe Lucia
Thanks Greg, I have pretty much decided to use a locking mount as a safety issue. I know that my June built car probably didn't have them. I will take the deduction as my car will be driven on a regular basis. Thanks for the helpComment
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Re: Question for Joe Lucia
Brad-----
Briefly, the 3990916 will fit and function perfectly for your application. Actually, the GM #3990916 is a motor mount KIT. It contains 1 GM #3980701 mount + hardware for installation.
The current GM mount KIT, GM #6258154, contains one GM mount #330973 + hardware for installation.
The GM #3980701 and GM #330973 mounts are identical EXCEPT for one feature. That feature involves the oblong spacers welded to the frame of the mount and through which the through bolt passes. The 3980701 used a cast or forged spacer. The 330973 uses a spacer fabricated from bar stock with a slight space where the ends meet. Very, very difficult to see this feature when the mount is installed on the car.In Appreciation of John HinckleyComment
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Re: Question for Joe Lucia
Joe, Which of these would you say would be the most authehtic or should I be looking for another #. I know these cars had non locking mounts but as a safety feature I am going to use locking mounts. I have the 6258154 But was not sure if there is something better to use or should I be looking for NOS mounts. I have another part question for you. What does a 3995641 water pump pulley fit. I have 1 that came with my car and 1 NOS both the same # The problem I am having is when I put the pulley on the hub it hits the water pump (not by much). I thaked to Bill Mock and he said that the hub measurement off of a flat surface is 5.75 '' and that is what I have. So i am wondering if the pulley is correct. The water pump is a 284 casting. Thank you for all you do!Comment
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Re: Question for Joe Lucia
Brad-----
As far as NCRS/NCCB is concerned at the present, 1969 Corvettes were not originally equipped with locking style mounts. While it is possible that some were, they would not currently be judged correct for a 1969. So, it really doesn't matter which mount you use---if you use a locking style it's going to be judged incorrect. In a case like this, there are no "degrees of incorrectness". In other words, if you use a 3980701 mount (as supplied with the 3990916 kit) as was used on 1970-72 Corvettes, it's not going to be judged "better" than if you use a later style incorrect mount.
I would absolutely NOT pay a premium to obtain a 3980701/3990916 mount over the current GM mount, especially in your case.
A GM #3995641 pulley is a SERVICE replacement pulley for some 1966-68 Corvette applications. It replaced pulley GM #3883235. The difference between the pullies is a slight difference in the configuration of the "hat" section + the fact that, as I recall, the 3995641 has no internal reinforcement. This may require the addition of a seperate reinforcement to obtain proper water pump clearance and/or belt alignment.
No matter in your case, though. Neither the 3883235 nor the 3995641 were ever originally used for a 1969 L-36 application.
Your application used a 3 groove pulley of GM #3889372.In Appreciation of John HinckleyComment
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Re: Question for Joe Lucia
Joe Thank Again. Any idea where to get the correct pulley? Was there a service replacement? Was the 3995641 used with the 284 pump?Comment
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Re: Question for Joe Lucia
Brad-----
A reproduction of the 68-70 pulley is available from reproduction sources like Dr. Rebuild; it's LONG discontinued by GM. There was once-upon-a-time a SERVICE-only replacement pulley for the original 68-70 big block pulley. That replacement pulley was GM #3995644. It's long-since GM discontinued, too. It was quite similar to the original except for slight differences in the hat section and the lack of the internal reinforcement.
The GM #3995641 pulley was never ORIGINALLY used with the '284' or any other water pump. Being a SERVICE-only piece, it was, by definition, never originally used with anything---it's SERVICE-only.
By the way, I gave an incorrect part number for the pulley that the 3995641 replaced. The original part number was GM #3848904 and NOT 3883235.In Appreciation of John HinckleyComment
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Re: Question for Joe Lucia
Hi Joe, I am assuming that on 3 groove pulley the rear belt was crank, water pump and alternator the middle was crank, water pump and PS and the front was water pump and smog pump . Does that sound right? Thanks againComment
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Re: Question for Joe Lucia
Brad-----
Generally, the rear groove was captive (crank, waterpump). Front groove was AIR, waterpump. Middle was waterpump, crank, power steering OR waterpump, crank alternator for non-PS apps.In Appreciation of John HinckleyComment
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Re: Question for Joe Lucia
Joe, thanks for the pulley information. Back to my motor mount question. Doyou think that the non safety repro (since it doesn't seem like NOS is available) mounts would last in my car or should I stick with my original plan? I understand it is only a 5 point deduction. ThanksComment
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Re: Question for Joe Lucia
Brad-----
I only recommend the use of locking style mounts for all 63-82 Corvettes. For a driven car, it's not worth risking the consequences of a broken mount for a relatively small facet of originality.In Appreciation of John HinckleyComment
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Re: Question for Joe Lucia
Joe thats what I was thinking. Thanks againComment
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Re: Question for Joe Lucia
Joe what was the original finish on the 3889372 pulley? I found one and it almost looks like black phosphateComment
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