C3 BB Radiator Baffle & AIM

[Shawn Soeder]

I'm restoring a '68 427 car. I noticed the radiator baffle illustrated in the '68 AIM. I also read posts in the archives that this baffle was only used on small block cars with steel shrouds. On the other hand, the AIM clearly shows this baffle used in conjunction with the 427 fiberglass shroud (L36 option, sheet A12).

Also, the AIM shows a modification to the L36 shroud to add a "ring" to the bottom half, which appears to be basically an extension of the shroud (sheet A13). Is this something that was actually done in production?

I'm pretty new to corvette restoration and this group, so forgive me if this is a dumb question. Perhaps this is just a case of the AIM showing what the engineers wanted, but the production guys didn't do it?

[Joe L.]

Re: C3 BB Radiator Baffle & AIM

Shawn-----

It was always my understanding that the lower baffle was used only for 68-72 with small block and round metal fan shroud. However, it's possible that it was used for 1968's with big blocks, too. I'm not clear on fitment with the 68 fan shroud or with the later big block fan shroud. The 68 shroud is different, though, and there may be a way to install the baffle.

As far as the shroud extension ring goes, I believe that it was originally installed for all or, at least, most 1968 big blocks.

Hopefully, we'll hear from some folks with original 1968-72 big block cars regarding presence or absence of the lower baffle and from some folks with 68 big blocks regarding the extension ring.

[Dick W.]

Re: C3 BB Radiator Baffle & AIM

'68's did have a fan shroud extension for the "plastic" shroud, long discontinued by Generous Motors. However there are some good repro's being made. Sermershiem's Corvette makes the one that I have used. Very good repro

'68's 427's did use a support to hood seal or air dam. Good ole Doc Rebuilt has a reproduction, his part #1274304. I also believe that this year the seal attached via staples.

[Mike Baker]

Re: C3 BB Radiator Baffle & AIM

The way I understand the lower baffle:

1. BB cars did not have the lower baffle.
2. SB cars without AC did have the lower baffle.
3. Cars with AC (both SB and BB) used the fiberglass BB shroud with an extension ring.

Having said that, my car was not all original when I bought it and I questioned the AIM as it relates to the baffle also. I don't think it could fit with the fiberglass shroud.

I don't have the AIM at hand to check the page you're refering to, but I remember the extension ring shown clearly in the AC section.

[Shawn Soeder]

Re: C3 BB Radiator Baffle & AIM

Unless I'm reading something wrong, the extension ring and baffle are both illustrated in the L36 option. This appears to have been redesigned in December of 1967. This would indicate that this was used even without AC.

For air conditioning, the AIM shows that the big block fiberglass shroud was used with a different, longer two-piece extension (C60 sheets B3, B4). The use of the single lower shroud extension (BB w/o AC) appears to have been cancelled for AC cars and the longer shroud extension added in late '67.

[Henry J.]

Re: C3 BB Radiator Baffle & AIM

Shawn, I agree with your interpretation of the AIM.

The TIM&JG indicates only that "All [cars] with copper radiators used a two-piece shroud with a narrow removable extension bolted to the bottom". According to the TIM&JG, all 68 L36's had copper radiators. No mention is made of the lower baffle.

For what it's worth, my car (L36 w/o air) has neither the bottom shroud extension nor the lower baffle, but mine is hardly an originality candidate. Nothing here a masochist can't fix!