305 header size ???

71novastocker · 02-19-2020, 07:24 PM

What would be the best header size to run. The combo is 175/248. Thanks.

dragracer502 · 02-20-2020, 11:20 AM

Found power on the dyno going down from 1 &3/4 to 1 & 5/8

Brian Fink · 02-20-2020, 11:27 AM

The late great Jere Stahl strongly recommended 1 5|8 on my 305 ; it made real good horsepower .

Mark Callanan · 02-20-2020, 02:45 PM

Quote:

Originally Posted by Brian Fink

The late great Jere Stahl strongly recommended 1 5|8 on my 305 ; it made real good horsepower .

How much Horse Power love to know??
lol

71novastocker · 02-20-2020, 06:13 PM

Quote:

Originally Posted by dragracer502

Found power on the dyno going down from 1 &3/4 to 1 & 5/8

Just straight 1 5/8" or with a step.

71novastocker · 02-20-2020, 06:17 PM

Quote:

Originally Posted by Brian Fink

The late great Jere Stahl strongly recommended 1 5|8 on my 305 ; it made real good horsepower .

Just straight 1 5/8" or is that a step header.

Billy Nees · 02-20-2020, 06:33 PM

I would probably do a 1 1/2 to 1 5/8 step.

jmoneyfoot · 02-20-2020, 06:58 PM

My dish piston 305 2bbl made the most with 11/2"-15/8"step with a merge collector

Jim Caughlin · 02-20-2020, 07:28 PM

Based on past experience, assuming it is an auto trans, I'm thinking that 1 1/2 / 1 5/8 is going to work best with a 2 1/4 to 2 2/4 merged collector.

Tom Moock · 02-21-2020, 01:55 AM

Brian Fink, I thought you had Jack Davis small tube step headers on your car, per 2007 Hemmings Muscle Machines.

02-19-2020, 07:24 PM	#1
71novastocker Junior Member Join Date: Apr 2011 Posts: 17 Likes: 0 Liked 1 Time in 1 Post	305 header size ??? What would be the best header size to run. The combo is 175/248. Thanks.

02-20-2020, 11:20 AM	#2
dragracer502 Member Join Date: Nov 2008 Posts: 163 Likes: 6 Liked 10 Times in 8 Posts	Re: 305 header size ??? Found power on the dyno going down from 1 &3/4 to 1 & 5/8 __________________ F Federico NHRA J/SA

02-20-2020, 11:27 AM	#3
Brian Fink Member Join Date: Jul 2007 Posts: 173 Likes: 39 Liked 28 Times in 9 Posts	Re: 305 header size ??? The late great Jere Stahl strongly recommended 1 5\|8 on my 305 ; it made real good horsepower .

02-20-2020, 06:33 PM	#7
Billy Nees VIP Member Join Date: Oct 2002 Location: On a hilltop in Pa. Posts: 4,494 Likes: 3,596 Liked 7,731 Times in 1,739 Posts	Re: 305 header size ??? I would probably do a 1 1/2 to 1 5/8 step. __________________ Billy Nees 1188 STK, SS I'm not spending 100K to win 2K

02-20-2020, 06:58 PM	#8
jmoneyfoot Junior Member Join Date: Dec 2015 Location: waconia mn Posts: 92 Likes: 21 Liked 9 Times in 5 Posts	Re: 305 header size ??? My dish piston 305 2bbl made the most with 11/2"-15/8"step with a merge collector

02-20-2020, 07:28 PM	#9
Jim Caughlin Senior Member Join Date: Mar 2002 Location: Woodburn, Or Posts: 685 Likes: 82 Liked 805 Times in 245 Posts	Re: 305 header size ??? Based on past experience, assuming it is an auto trans, I'm thinking that 1 1/2 / 1 5/8 is going to work best with a 2 1/4 to 2 2/4 merged collector.

02-21-2020, 01:55 AM	#10
Tom Moock Senior Member Join Date: May 2004 Posts: 801 Likes: 1 Liked 10 Times in 6 Posts	Re: 305 header size ??? Brian Fink, I thought you had Jack Davis small tube step headers on your car, per 2007 Hemmings Muscle Machines. __________________ Tom Moock 5704 STK