Hello all, was just wondering if anyone knows how much is involved in changing my 4GC Rochester to another Carburetor. Iv'e had just about enough of mucking around trying to get this one working right, I'm just worried there might be a lot of hassle with linkages etc, Does anyone have any options they could pass on to me? I just think it might be time to fit another carby. as this 4GC is the original and may be past it's use by date. Any advice would be much appreciated, Cheers Ray.

 

It depends on what you're trying to change to and if the transmission is an automatic. Changing to another Rochester for an automatic transmission equipped vehicle would be easier than another make carburetor. The transmission must have the correct linkage to shift properly. Unless the original carburetor is really in sad condition physically, I'd probably try to do a good overhaul.

 

Somtimes it does behoove us to acknowledge our limitations. If you have tried your best. all to no avail, it may be more than worth it to send the carb off to a quality rebuilder. Could be a money well spent on your part.

Quality carb rebuilders are out there :
Sparky's Carb - https://www.sparkyscarbs.com/
Daytona Pats Co - https://daytonaparts.com/find-your-carburetor-kit.html

Good luck!

 

In addition to having to figure out the linkages, most popular aftermarket carburetors do not share the same stud spacing as the 4gc, requiring either a new manifold or an adapter plate if one is available. I would personally prefer to find a good used 4GC to rebuild or send it to a reputable re-builder, for originality's sake.

As a side note, If you've done everything to your current carb and it still won't run right, you could be dealing with a worn out throttle shaft - this would cause a rather difficult to detect vacuum leak and can only be fixed by machining the carb body. Also, occasionally one of the castings is warped, which you can check with a good machinists straight edge and feeler gauges. Slight warping is sometimes fixable with an additional gasket, if not, the casting is junk.

 

They are adaptable but as mentioned above to do so will test your fabrication skills. If this carb is beyond a rebuild why not get another 4gc and save the grief of making all new linkage? That carb was made for years on many GM and other makes they are out there. I realize you are in the down under but ebay wont hold it against you, most ship over seas... Tedd

 

Another option is to spend your time and money towards installing the J2 option. Intakes a fairly cheap and you can run off the center 2bbl. With block offs on the ends. You can add the end carbs and parts as funds allow.

 

Hello again and a Merry Christmas to you all, Thanks for your replies, Well one thing i have learnt is to have patience if anything when owning an old car !! I was checking the vacuum lines as OZZIE suggested and low and behold the line that runs from the carburetor to the distributor was loose right down where the fitting screws in. i mean the fitting was just in by one or two threads it was lucky it didn't fall out .I have also replaced the rubber T connection that joins the two vacuum lines as well. I took the car for a twenty mile drive across the bay today and she drives really well. Just wanted to say thanks again for all of your help, Still Learning, Ray.

 

Wow ! You went from a very expensive scenario to a really cheap one .
How nice !

 

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