3977591 oil pan baffle

[Brad S.]

Does the 3977591 pan use the baffle # 3967584 and do you have to change the studs as with the current GM replacement pan? thanks

[Joe L.]

Re: 3977591 oil pan baffle

Brad-----

You do not have to change studs with the current replacement oil pan, GM #14091356. However, it's recommended that the baffle be replaced with the 3967584. Actually, the 3967584 was used for all 1970-74, anyway, so if the car happens to be one of those years, then you're exchanging "like-for-like" as far as the baffle goes. Earlier Corvette big blocks used baffle GM #3873878.

The GM #3977591 and successor, the current GM #14091356, are absolutely identical except for 2 things:

1) the 3977591 has corner reinforcements wheras the 14091356 does not. The reinforcements are available in reproduction and can be easily added without the need for spot welding;

2) the 3977591 was supplied unpainted OR painted Chevrolet orange; the 14091356 is powder-coated black.

That's it; those are the only differences. I'm amused whenever I see guys pay Big $$$$$ for a 3977591; sellers love it.

The 3977591 and 14091356 (actually, the pan is GM #14095703 but it's supplied as part of a KIT of GM #14091356 which includes the pan, baffle and instructions) were designed for use with the longer stroke 454 cid engine first used for 1970. To accomodate the longer stroke, the internal baffling in the pan was revised (shortened) and the baffle was revised to lower it as installed. The studs were NOT changed at that time (although they were revised for 1967, well before the 454 engines were released).

You can use the early style baffle (65-E69) with either the 3977591 or 14091356 pans. However, you are then sacrificing some of the efficiency of the baffling SYSTEM (i.e the welded-in internal baffling + external baffle). I (and, GM) don't recommend this. If you use the 3977591 or 14091356 pans on a 65-69 engine, you should install the 3967584 baffle, too.

I don't think that you can use the 3967584 baffle with the EARLIER pans, though. Notwithstanding the fact that the GM #3967584 replaced the 3873878 for SERVICE, I believe that the 3967584 will interfere with the welded-in oil baffling of the earlier pans. I'm not 100% sure of this, though; I've never tried it to confirm interference.

[Brad S.]

Re: 3977591 oil pan baffle

Joe, if I use the 3977591 pan and 3967584 baffle on my 69 427 I would not have to change studs or do I have use the 454 studs to get the bolt that goes to the oil pump to work. Thank you

[Joe L.]

Re: 3977591 oil pan baffle

Brad-----

The studs that you have currently installed (assuming that they are original studs) are exactly the same as those originally used for 1970-74 Corvettes which originally used the 3977591 oil pan and the 3967584 baffle.

If by "bolt that goes to the oil pump" you are referring to the bolt (actually, a stud) which retains the oil pump to the rear bearing cap, that stud was the same for all 65-74 Corvette applications.

[Brad S.]

Re: 3977591 oil pan baffle

Joe, Thank you