Big block headers

[74kay5]

Trying to decide between Flowtechs and Headmans longtubes. Both are 1 3/4 primaries and are both a decent quality header. The flanges are getting cut off and o2 bungs are being added for my Gen III motor so I'm not looking for anything ceramic coated (just wanted to eliminate people commenting on that). Suposidly the big block ports have the same spacing as the Gen III's. I just need to decide on a set and check the fit. Mainly concerned about fitment next to the shackle. I have a set of Edelbrock TES headers for my old smallblock and they came too close to the shackle. Any thoughts?

 

[badmix]

NO matter what header you get, it could be hit or miss. I had some Hooker headers that hit the pass. side shackle. A couple cranks on a pry bar got it lined up. I just recently installed some new to me headers and they fit great, but sadly I dont know who made them. Some ppl speculated they are FLowtechs. THe hookers also hit my linkage for my shifter, it made shifting the column shifter a lil harder.

The top one is the hookers, the bottom one is mystery header. The bottom one was lighter as well. But it fit great, no tweaking involved at all.

 

[rcamacho]

I'm running Thorley headers on my BBC rig. Top quality. My only gripe is the passenger side runs very close to the frame rail and fuel line.

 

[bigblock72]

The port spacing is no where even close between a big block and an ls motor. Your better off buying headers for an ls and modifying them to fit your chasis. PM ryanb or search ls headers for details.

 

[74kay5]

The port spacing is no where even close between a big block and an ls motor. Your better off buying headers for an ls and modifying them to fit your chasis. PM ryanb or search ls headers for details.

I was running the LS1 F-body headers with a small notch in the drivers side, but have a new frame now and don't want to go that direction again. Currently running stock LS1 F-body manifolds temporarily to drive it.
How far off is it?

Dougs LS1 swap headers for the 69-72 and his big block headers look about the same.

 

[74kay5]

Aren't those SBC headers?

NO matter what header you get, it could be hit or miss. I had some Hooker headers that hit the pass. side shackle. A couple cranks on a pry bar got it lined up. I just recently installed some new to me headers and they fit great, but sadly I dont know who made them. Some ppl speculated they are FLowtechs. THe hookers also hit my linkage for my shifter, it made shifting the column shifter a lil harder.

The top one is the hookers, the bottom one is mystery header. The bottom one was lighter as well. But it fit great, no tweaking involved at all.

 

[bigblock72]

Here is a picture of the different flange gaskets. You can decide if it's a project you want to tackle.

I built my headers from scratch, I started with some big block headers thinking they would be close enough to modify. By the time I got them cut to line up I was pretty much had nothing left of what I started with.

 

[74kay5]

Here is a picture of the different flange gaskets. You can decide if it's a project you want to tackle.

I built my headers from scratch, I started with some big block headers thinking they would be close enough to modify. By the time I got them cut to line up I was pretty much had nothing left of what I started with.

Holy crap they're not a close as they seem after all, well there goes my idea. Any way you can build me a driver's side header?

 

[74kay5]

Talked to pacific fab and I'm giving up the big block header mod idea. Might end up modifying my F-body mac's but I'm going to give it one last shot before cutting them up and grab a set of pacesetter f-body headers and see how they fit. There is a guy on performancetrucks.net who has them on a 2wd C10 with a 6.0L 4L80E.

 

[badmix]

Aren't those SBC headers?

Yes they are, but I wanted to show the different styles between the two brands you mentioned. Not all headers are created equal.