I did a plethora of searching and found some answers, conflicting opinions...so here goes it.

I'm yanking the stock carb'd 305 and dropping a run of the mill, old school 010 block 383 into my '86 z28. Trying to figure out some header options and wanted to get some opinions on my specific setup and performance goals.

As it sits right now, the 383 that's going in is about 420hp. It's got Holley SysteMAX Aluminum Heads - 184cc/68cc Runners, 2.020/1.6 Intake/Exhaust Valves. Comp Roller Cam, .490/.490 lift, 238 duration @ .050. I'll probably swap a more aggressive cam in there and eventually put AFR's on. Over next winter I'm rebuilding and putting a procharger on it. All said and done, expecting ~600-650fwhp with boost.

The burning question - 1 5/8 shorties, or 1 3/4 LT headers? I'm currently between the Hooker 2460's (1 5/8 shorties), Doug's d3321's, and Hooker Super Comp's which are both 1 3/4's LT headers. I currently have the stock manifolds, y pipe and a 3" Magnaflow cat-back that came with the car...so I need a new y-pipe as well. I want to make this work with the least amount of stress possible. Will the 2460's choke my motor or will they be fine? What about after boost is added? I read everything from never to use 1 5/8 headers on a 383, to 1 3/4 headers are overkill. So many conflicting opinions, so I figured I'd just ask.

Also, the LT header route is not only more of a PITA to install from what I can gather, and it will cost nearly twice as much. It seems like the 2460's are much more cost effective and matching y-pipe will essentially bolt right up. Just weighing my options. Any input would be appreciated!

 

I would go 1_3/4 LT or 1_3/4 shorties like dyno don esp if you are going to pro charge

If you go 2460 You will need to modify the merger on that Y pipe because it necks down bad and will be an issue.

 

Look here if you want the best

https://www.thirdgen.org/forums/exha...ml#post6208833

 

Dyno Don shorties are the go to, if you don't care about ground clearance then go with long tubes lol