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I run 1 5/8 on my 383 that has been 1.47 6.89 99MPH car weights @3200 w/driver.From reading some older post it appears based on HP I am right on the edge of the 1 5/8 being to small and the 1 3/4 being to large.
Would 1 3/4 headers be worth any Et or would it just be a waste of money.


Currently running Edelbrock RPM heads was told if I swapped to a set of Victor Jr with no other changes i would pick up right at 2 tenths. Does that sound right.
I know a guy that has a set for sale and actually have someone interested in buying my RPM's. Means in good air i would be running high 6.60's.
 

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Is this on motor or spray??
 

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I run 1 3/4" headers on alot of small blocks such as 292, 331, 355's and they work fine, the stick cars have had 1 7/8" headers on them
 

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you may see a bit - a tenth or 1-2 mph.
you should be makin just under 500hp
But if you plan on upgrading to better heads I'd go for 1 3/4" headers
 

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I run 1 5/8 on my 383 that has been 1.47 6.89 99MPH car weights @3200 w/driver.From reading some older post it appears based on HP I am right on the edge of the 1 5/8 being to small and the 1 3/4 being to large.
Would 1 3/4 headers be worth any Et or would it just be a waste of money.


Currently running Edelbrock RPM heads was told if I swapped to a set of Victor Jr with no other changes i would pick up right at 2 tenths. Does that sound right.
I know a guy that has a set for sale and actually have someone interested in buying my RPM's. Means in good air i would be running high 6.60's.
Swap to a set of 195 AFR heads and the larger header your questioning and I bet you would see closer to a half second improvement (I would anticipate close to a 50 HP gain).

Either way I think the swap to 1.75 primary pipes wont hurt you currently (probably help a little bit) and work even better with a different set of heads in your future.

Good luck,
Tony
 

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I dynoed my 388 with 1 5/8" headers ans 1 3/4" headers. picked up 15hp on top and didn't lose any torque. This is a 480hp engine.

Swap to a set of 195 AFR heads and the larger header your questioning and I bet you would see closer to a half second improvement (I would anticipate close to a 50 HP gain).
I switched from RPM's to Pro Action 220's and picked up 50hp. ET went from 12.26 to an 11.75. I don't think you'll regret making that change.:thumbsup:
 

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I dynoed my 388 with 1 5/8" headers ans 1 3/4" headers. picked up 15hp on top and didn't lose any torque. This is a 480hp engine.



I switched from RPM's to Pro Action 220's and picked up 50hp. ET went from 12.26 to an 11.75. I don't think you'll regret making that change.:thumbsup:

Good info...thanks!
 

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I have 1 5/8 headers on my 427 small block with 220 cc heads. I am still running 11.70's on average. Its just hard to find an off the shelf header that will fit angle plug heads and a wedge style oil pan. The hooker super comps 2116 hit my oil pan.

Dave
 

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I have 1 5/8 headers on my 427 small block with 220 cc heads. I am still running 11.70's on average. Its just hard to find an off the shelf header that will fit angle plug heads and a wedge style oil pan. The hooker super comps 2116 hit my oil pan.

Dave
2116 dont hit mine but i run the percys header gaskers which are thick. The headers i installed are 1 3/4" and the passenger side is tightest and one tube goes right in front of the drain plug, i use the Moroso 20191 oil pan
 

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2116 dont hit mine but i run the percys header gaskers which are thick. The headers i installed are 1 3/4" and the passenger side is tightest and one tube goes right in front of the drain plug, i use the Moroso 20191 oil pan
I should of cut that one pipe that hits my wedge, and re-positioned it, instead I took the headers back. Hedman hustler makes a 1 7/8 header which requires using a sub flange. I am not sure if that might be too big since they also have 3 1/2 collectors.

Dave
 

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John,

That 480 HP was with the large tube headers. Made 465 HP with the small tubes. Although 1 tube on each side was crushed half flat to fit the chassis. So it might not be a totally fair comparison. Large tubes were brand new.
 
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