So I ordered a new holley carb because my 4165-6210 was leaking gas, not idling properly, and would stall on braking. Unfortunately I didn't think to check bore type and got a square bore 4150 instead of the spread bore that my stock l-48 intake requires. From what I've read on these 6210s the flood-on-braking problem is extremely common even when floats are properly adjusted. So, I'm considering my options:

in order of preference

1. spreadbore to squarebore adapter
2. return the 4150 and get another 4165-6210
3. return the 4150 and get an Edelbrock qjet
4. rebuild the 6210
5. pay somebody else to rebuild the 6210

I have a '75 4spd, small block l-48 with 1 5/8 headers, true dual 2 1/2", magnaflows, stock hood, stock dual snorkel housing, stock internals. I plan on getting a zz4 crate soon, so I am hoping that if I buy a new carb I can re-use it on the zz4. The zz4 crate seems to support spreadbore or squarebore equally with no adaptors.

Is an adapter appropriate here? I read briefly that with a small block it should fit under the stock hood with little to no perf loss. On the zz4 I could toss the adapter.

I'm hesitant to get another 6210 because as far as I know the stall-on-braking problems would still be there.

I'm okay with the idea of Edelbrock branded Qjets though I don't know much about them, heard they may run lean.

I have the Holley techbook so I guess I could rebuild the 6210 but I'm afraid it'll take me forever and I want to get back on the road.

Having somebody else rebuild the carb seems expensive and time consuming enough that I'd rather spend a extra for a new carb than go this route. Again, trying to get back on the road.

Any advice?

 

Why not get a square bore performance manifold to go with your new carb?

 

The Edelbrock 2101 intake can be used with a spread-bore or square-bore carb. The other Holley option is the 4175 spread-bore carb. I bought mine from Summit and it has worked well. I did have to deal with a couple of issues because of the cowl induction hood and stock air cleaner though.

 

I considered the new air intake route but I have no idea how hard it would be to swap. Getting the carb off was really easy. Again, it would have to be something appropriate for a zz4 also. The zz4 long block comes with an intake but I have no idea how good it is. If it would make sense to get an intake that I can put on my l48 and then move to the zz4 later I am game. Edelbrock RPM Performer with drop base cleaner maybe? Gotta fit under the stock hood.

 

Rebuild what you got. Always good to learn and the least expensive option. They are easy to rebuild and there is plenty of info on the net. Good luck with it. mike...

 

edelbrock no longer makes quadrajets. they still make parts. the holley spread bore is a good choice . a good rebuilt quadrajet done by someone who knows what he is doing is a good option too