Another Header Question

[DAVE00]

Ok, all I appreciate the help that everyone has given regarding my exhaust question on my LT-1 (383), but got one more for ya. Is there anyone who has an LT-1 with JBA headers that has lowered their f-body with eibach's? If so, got a few questions:

1) Do you have problems with burning ignition wires and if so what did you do besides wrapping the headers cause that looks so ugly?

2) Who would you recommend to make a custom y-pipe (Houston area if possible)?

3) What brand of highflow cat would you recommend that has good ground clearance?

4) Lastly, are the JBA's good, are is there another brand you would recommend (Shorty style w/egr hookups for emissions) that might work better for flow and fit?

Ok, that's it, once again thanks to all for your help.

[Injuneer]

I had the JBA 1-5/8" headers on my "bolt-on" stock engine. I don't think they were really big enough for that engine. I doubt they will support any sort of a healthy 383. A heavy breathing 383 needs a 1-3/4" primary.

The JBA's don't even start as 1-5/8" primaries.... they are a "step" header design. The first couple inches of each primary is a 1-1/2" diameter. Then, in what they call an "anti-reversion" design, they add a small weld bead to the port. Now the flow is really choked, IMHO.

The step design is intended for basically stock setups, where you need a little extra exhaust gas velocity at low RPM to keep the cylinder scavenging up. It helps on the bottom end, but if you try and put too much flow through it at the top end, it becomes a cork.

Possibly there is a larger diameter set of JBA's that I am not aware of. What diameter are your primaries?

You really need to look at something like the AS&M mid-length headers.

[DAVE00]

Wow, Injuneer, you really know your stuff and thanks for all the input. I have never heard of AS&M mid length headers, where could I look at a set and would they work ok on ground clearance? As to the JBA's your right they were originally put on the car pre 383 days and now I do feel like they are a little constricting. Just to note I am using the AFR 195cc heads, any specific recommendations for applications to best fit these?

[Injuneer]

Everything I have seen about the AS&M's, except perhaps access to one plug is positive. I have a set I bought used, from a friend who made 850flywheelHP with them on a Vortech S/C'd 383. No ground clearance problems. They are expensive. Supposedly, the RK Sport headers are just about the same, and a little cheaper.

They are no different that any other single-cat headers, with a supplied Y-pipe that connects the drivers side to the cat by wrapping around the front of the oil pan.... just like the JBA's. Mine were modified to point straight back on both sides, so I can run a dual exhaust, but the work wasn't done very well. In spite of that, they support nearly 800HP on my nitrous 383.

You can get them at T.Byrne Motorsports:

http://www.tbyrnemotorsports.com/lt1catalog.html