Suggestions on primary header size for modded 305
12-10-2023, 09:08 AM
#1
Suggestions on primary header size for modded 305
Hey folks,
short question:
Im searching for headers for my 88 formula. The 2055 hooker arent avaiable at summit. So im looking around and found american racing headers with 1 3/4" primary tubes. Is it overkill for my engine or would you suggest going larger than 1 5/8" (hooker 2055 f.e.)?
There is a large debate about this topic and I know either 1 5/8 or 1 3/4" would be the way.
Background and technical data:
-rebuilt 305 bored .030" over
-Trickflow 175cc heads
-10.2:1 static, 9,5 DCR
-206/212 in/ex @ .050 cam
-.512"/.520" lift @ valve
-3" exhaust, but with "ported" exhaust manifolds till yet.
-ported tpi manifold, but soon want more rpm (swap to pro flo 4 xt)
What do you guys think?
Im pretty sure to go for more rpm in future.
Greetings,
Chris
short question:
Im searching for headers for my 88 formula. The 2055 hooker arent avaiable at summit. So im looking around and found american racing headers with 1 3/4" primary tubes. Is it overkill for my engine or would you suggest going larger than 1 5/8" (hooker 2055 f.e.)?
There is a large debate about this topic and I know either 1 5/8 or 1 3/4" would be the way.
Background and technical data:
-rebuilt 305 bored .030" over
-Trickflow 175cc heads
-10.2:1 static, 9,5 DCR
-206/212 in/ex @ .050 cam
-.512"/.520" lift @ valve
-3" exhaust, but with "ported" exhaust manifolds till yet.
-ported tpi manifold, but soon want more rpm (swap to pro flo 4 xt)
What do you guys think?
Im pretty sure to go for more rpm in future.
Greetings,
Chris
12-10-2023, 09:22 AM
#2
Member
Re: Suggestions on primary header size for modded 305
A 1 5/8 will be fine and may be better w the 305/tpi. I bet you'll make better torque w that setup. I have a pro flo xt w a 350 and it likes to rev more. I had Edelbrock tes 1 5/8 headers and switched to dons 1 3/4. Didn't do a back to back dyno so I can't say power wise. I don't think my seat of the pants dyno is capable of telling. The pro flo makes great power either way. I'd consider trying to get a set of dons headers while he's still doing them if you're gonna try and go 1 3/4.
12-10-2023, 09:52 AM
#3
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dmccain (12-12-2023)
12-11-2023, 04:13 PM
#4
Re: Suggestions on primary header size for modded 305
Shorty (really these used to be known as 3/4 length and there are shorter headers) are more about HP (overall flow) and less about torque (tuning that flow) than long tube headers. You're about in the middle with that combination, long tube 1-5/8" headers will get you the best low end and mpg, 1-3/4" shorty headers will likely make more HP, less torque, 1-3/4" long tubes will likely be the best of both worlds. This is all assuming that everything else matches. You'll likely not have enough airflow with the TPI manifold to really take advantage of the 1-3/4" headers.
Not a clear "do this" answer but not really a clear "I'm doing this and I want this" question.
Not a clear "do this" answer but not really a clear "I'm doing this and I want this" question.
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