Hi, I’ve done some research, but still don’t really have a clear answer.
I’m in the middle of converting my 1968 Firebird (originally a 350/th350 car w/ floor shift and console) to a manual transmission. In my research prior to tearing the car apart, I assumed I’d need to cut the manual trans shifter hole in the tunnel.
I took the engine and trans out yesterday, and found that I already have a large, oval shaped hole in the tunnel. It was sealed up with what looks to be a factory rubber boot that the shifter cable went through. The hole looks factory made, and is sort of rough on the edges; like it was cut with a torch.
What’s the deal? I thought only 67 automatic cars had the manual shifter hole from the factory. Then I also read that only 69 models had the oval shaped / rough cut hole.
I’ll try to post a picture when I can. Hopefully my situation and question make sense.
It's been many years since I saw the shifter hole in my TH400 equipped '68 but here is a GM 9794252 shifter cable I keep around as a spare. Note the shape of the boot. Is that oval like your '68 cut-out?
Also, I had thought the TH350 started being used in '69?
Thanks for the reply. That looks like the boot. Firebird Central sells a repop that is said to be for 68-69 cars. https://www.firebirdcentral.com/ProductDetails.asp?ProductCode=TRA%2D2030&CartID=2
That is the shape of the hole as well. I’m guessing this would be the same hole a manual car would have, but that’s what I’m trying to figure out. From my research, only 1969 Camaro manual cars have this oval, rough cut hole. Couldn’t find much info on the subject relating to Firebirds.
And I thought my car was a th-350 originally, but maybe it was a powerglide? It’s got a 200-4R in it now.
Mine really looks like the manual hole found on 69 Camaro 4 speed models. A plasma cut, oval shaped hole with no reinforcement plate. In comparison, 1968 Camaro automatics just have a small shifter cable hole.
This document is referencing Camaros, but you can see the confusion:
“All 4-speeds and floor shift 3-speeds have a hole in the transmission tunnel for the shifter. The style used mainly in 67 & 68 was a clean-cut rectangular shaped hole which had a reinforcing ring welded to the underside of the tunnel around the shifter opening. The reinforcement ring was used on the following applications: all 1967 floor shift models (AT and MT), 1968 all MT floor shift, 1968's with the TH400 M11 floor shift (w/o console), and 1969 models with 3-speed manual w/o console. The hole cutout for 1969 models equipped with a 4-speed was smaller and more "oval shaped" than the other design. It was also rough cut with a torch and did not use the reinforcement ring welded to the bottom of the tunnel.”
So the question is whether my oval “69 style” hole is in the correct 4 speed location. I don’t need the reinforcement plate. At least I see no reason for it. I’m really just wondering if I’ll need to patch my tunnel and make a new hole.
