Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: jk79ta on July 06, 2011, 06:42:09 AM

Title: carb. interchange
Post by: jk79ta on July 06, 2011, 06:42:09 AM

I have had to replace my 1979 pontiac 301 with a 1975 pontiac 400. I was wondering if the carb. from the 301 will work on the 400? Both are automatics.  Thanks.

Title: Re: carb. interchange
Post by: Cliff Ruggles on July 07, 2011, 04:38:09 AM

The 301 carb is the same basic casting, but not set up the same way.  They have a limited secondary airflap shaft angle, and leaner calibration....Cliff

Title: Re: carb. interchange
Post by: jk79ta on July 07, 2011, 05:43:50 AM

Thanks Cliff. I think I'll just put it on and see what happens. Do you think the differences you mention will have much of an effect on performance, or fuel efficiency? If I were to have you rebuild the carb, could you adjust those two things?

Joe

Title: Re: carb. interchange
Post by: Cliff Ruggles on July 08, 2011, 03:02:40 AM

The limitted secondary airflap angle is going to severely limit the power potential of the 400.  I'd grind some of the stop so it can open to the correct angle shown in our book. 

No problem at all recalibrating it for the 400.  I'm working on the same type 301 carb today headed for a 455 making 530hp.....Cliff

Title: Re: carb. interchange
Post by: jk79ta on July 08, 2011, 04:36:08 AM

Thanks Cliff. I'll take a look in your book and see if it's something I want to tackle. Then maybe next winter I'll send in to you.

Joe