2bbl to 4bbl switch

jmoneyfoot · 12-29-2019, 02:49 PM

Hey guys I run a dish piston 305 2bbl combo and am switching to a 4bbl, how much can I expect to pick up by just changing the intake and carb? Carb is a dean Oliver quadrajet. Any input is greatly appreciated. Thank you

Billy Nees · 12-29-2019, 03:17 PM

Ya know that you've got to change the heads and cam too, right?
If you're just changing the intake and carb to "play" with it, about 7-8 tenths.

jmoneyfoot · 12-29-2019, 04:19 PM

Thanks billy, that's what I was wondering, I know a cam change would be beneficial, I never even considered the heads. Thank you

Billy Nees · 12-29-2019, 04:33 PM

Unless you've got a 4V cam in the motor, a cam change would be mandatory. The 2V cam spec is bigger than the 4V cam spec.

jmoneyfoot · 12-29-2019, 04:42 PM

The specs are the same, the only difference is the intake valve is bigger in the 4bbl. This is a 78 nova chevy 305 2bbl combo going in a 79 malibu 305 4bbl

Billy Nees · 12-29-2019, 04:46 PM

Well OK then.

12-29-2019, 02:49 PM	#1
jmoneyfoot Junior Member Join Date: Dec 2015 Location: waconia mn Posts: 92 Likes: 21 Liked 9 Times in 5 Posts	2bbl to 4bbl switch Hey guys I run a dish piston 305 2bbl combo and am switching to a 4bbl, how much can I expect to pick up by just changing the intake and carb? Carb is a dean Oliver quadrajet. Any input is greatly appreciated. Thank you

12-29-2019, 03:17 PM	#2
Billy Nees VIP Member Join Date: Oct 2002 Location: On a hilltop in Pa. Posts: 4,485 Likes: 3,587 Liked 7,682 Times in 1,730 Posts	Re: 2bbl to 4bbl switch Ya know that you've got to change the heads and cam too, right? If you're just changing the intake and carb to "play" with it, about 7-8 tenths. __________________ Billy Nees 1188 STK, SS I'm not spending 100K to win 2K

12-29-2019, 04:19 PM	#3
jmoneyfoot Junior Member Join Date: Dec 2015 Location: waconia mn Posts: 92 Likes: 21 Liked 9 Times in 5 Posts	Re: 2bbl to 4bbl switch Thanks billy, that's what I was wondering, I know a cam change would be beneficial, I never even considered the heads. Thank you

12-29-2019, 04:33 PM	#4
Billy Nees VIP Member Join Date: Oct 2002 Location: On a hilltop in Pa. Posts: 4,485 Likes: 3,587 Liked 7,682 Times in 1,730 Posts	Re: 2bbl to 4bbl switch Unless you've got a 4V cam in the motor, a cam change would be mandatory. The 2V cam spec is bigger than the 4V cam spec. __________________ Billy Nees 1188 STK, SS I'm not spending 100K to win 2K

12-29-2019, 04:42 PM	#5
jmoneyfoot Junior Member Join Date: Dec 2015 Location: waconia mn Posts: 92 Likes: 21 Liked 9 Times in 5 Posts	Re: 2bbl to 4bbl switch The specs are the same, the only difference is the intake valve is bigger in the 4bbl. This is a 78 nova chevy 305 2bbl combo going in a 79 malibu 305 4bbl

12-29-2019, 04:46 PM	#6
Billy Nees VIP Member Join Date: Oct 2002 Location: On a hilltop in Pa. Posts: 4,485 Likes: 3,587 Liked 7,682 Times in 1,730 Posts	Re: 2bbl to 4bbl switch Well OK then. __________________ Billy Nees 1188 STK, SS I'm not spending 100K to win 2K