1979 GMC Cobra Jet

[DavidR]

What cid is the big block and what has been or is going to be done to the motor?
Get ahold of CP Performance @ (800) 225-9871
(they now manufacture Berkeley jets) and ask them to send you a copy of the rpm / horsepower absorbsion information on the various impellers. That will give you an idea of where to start. Your best bet will probably end up being an "A" impeller as it provides a good compromise on holeshot and top speed ( especially with a torquey 454).
If you use an impeller by a manufacturer other than Berkeley get this info from them as specs on other impellers sometimes vary by quite a bit even being the same designation ("A","AB",etc.).
Let me know if I can help.

[MichaelRP]

What cid is the big block and what has been or is going to be done to the motor?
Get ahold of CP Performance @ (800) 225-9871
(they now manufacture Berkeley jets) and ask them to send you a copy of the rpm / horsepower absorbsion information on the various impellers. That will give you an idea of where to start. Your best bet will probably end up being an "A" impeller as it provides a good compromise on holeshot and top speed ( especially with a torquey 454).
If you use an impeller by a manufacturer other than Berkeley get this info from them as specs on other impellers sometimes vary by quite a bit even being the same designation ("A","AB",etc.).
Let me know if I can help.

I just purchased a 1979 CobraJet with a 350 Old/Berkely setup, not sure how to tell what kind of setup it is to be honest. I don't know a whole lot about this boat, and I am looking for any help I can get. The boat is not currently running, trying to trouble shoot why its not firing, turns over plenty just won't fire a cylinder at all. Any help would be appreciated...

[79cobrajet]

I just purchased a 1979 CobraJet with a 350 Old/Berkely setup, not sure how to tell what kind of setup it is to be honest. I don't know a whole lot about this boat, and I am looking for any help I can get. The boat is not currently running, trying to trouble shoot why its not firing, turns over plenty just won't fire a cylinder at all. Any help would be appreciated...

Hello, I was wondering if you had ever gotten any useful info on the GMC CobraJet boat... I have a 1979 , 16 1/2 ft. that I just got and I am having one heck of a time locating info on this desighn too.

[MichaelRP]

Well I haven't found to much out about it yet no, what I do know is in the original post, I rebuilt the holley on mine and it is running like a beast, great boat, I have people I can ask if you have specific questions about the CobraJet