Rochester 2 barrel conversion?
 

Hi everyone,
I'm new to joining the club but have used the site for information for several years and purchased my 1968 k2500 with GMC 305e in 1991. I will get some photos loaded and give the history soon.
My question is- has anyone installed a Rochester 2jet on a 305? I have a lot of experience with the Rochester, they are dependable and easy to set up and are relatively inexpensive.
I'm guessing an adapter would be required and I am prepared to machine one from 1inch aluminium.
Any and all feedback is appreciated.

Re: Rochester 2 barrel conversion?
 

Few photos

Re: Rochester 2 barrel conversion?
 

Ricans:
Yes. I ran a duojet on my 305 and now have one on my 351e. Bolt holes lined up with studs on 305e, but t made an adapter plate because the gasket surface on the carb was a little bigger than surface of the manifold. I use 1/4" aluminum plate.

Hope that helps.
Regards
Steve

Re: Rochester 2 barrel conversion?
 

Thank you for the info. The studs lining should make for a less involved swap. Sounds like the adapter is needed to give the new carb more area to sit on. That's a lot easier than relocating the mounting hardware. Other than maybe having to swap the choke cable to the passenger side was there anything else I should prepare for?
Did you use the small or large bore 2bbl? I think they are two different mount patterns but can't remember for certain.
Thanks

Re: Rochester 2 barrel conversion?
 

Ricans:
A couple of pics are attached. IIRC, I flipped the choke shaft over and used a cable stop so I could retain manual choke on driver's side. Required fabbing a simple bracket to attach cable to as well. Pic shows adapter vs original riser for 305e. Pic is carb on 351e that has trapezoid base for magnum motor. Carb was from late sixties sbc in a Camaro. Not sure if small or large bore??

I hope this helps.
Regards
Steve
New Orleans

Re: Rochester 2 barrel conversion?
 

Thanks for all the info Steve. It looks like you did a real nice job on the adapter plate. Swapping the choke shaft is a great idea, not sure I would have thought of that. If memory serves me small bore 2jets came front and side inlet but large bore were all front inlet. So I'm going to dig up and rebuild a small bore and make the conversion. Ill have to wait till spring as she's my plow truck.
Thanks again for sharing your knowledge with me.
Rich

Re: Rochester 2 barrel conversion?
 

Rich:
You are welcome. Can't imagine taking your snow plow out of service right now... Lol.
Regards
Steve

Re: Rochester 2 barrel conversion?
 

Rich:
You are welcome. Can't imagine taking your snow plow out of service right now... Lol.
Regards
Steve

Re: Rochester 2 barrel conversion?
 

A few '68 305's actually were built with Rochester 2 bbls.. Be nice if you could find one of the Rochester 2 bbls. off a 455 Olds, those were pretty big.

Re: Rochester 2 barrel conversion?
 

I didn't know the v-6's came with the Rochester. I always found it strange that the 2bbl was put on large displacement engines. In the early eighties I ran a 307 with a 2jet in a dirt track car and it worked out real well,
Once I do the swap ill post some photos of the manifold, gaskets, spacer etc.
Thanks for the info