Headers

[MOBS]

Not sure I quite understand that statement. Please clarify for me-

Sorry, I was incorrect with the percentage, it's 160%

The heads on the 88-95 engines don't flow for squat in stock configuration, so with that in mind, your primaries don't need to be really big. 160% volume of the exhaust runners, I guess that should be clarified: In short, if you have a 1"-squared exhaust port, the port of the primary should be 160% of that, which is a 1.6"-squared opening. So that would be between a 1.4"-1.5" tube, 1.4" tube has an area of 1.54 sq in and 1.5" tube has an area of 1.77 sq in. The volume I mentioned wasn't exactly needed, I was using "volume" to express airflow, but if ya wanted to really measure it, you'd be measuring the volume of the last 1" of exhaust runner and first 1" of exhaust primary. Sorry if I can't make this any more simple, I'm not the best at explaining mathematical measurements; I would fail as a teacher, lol.

 

[stroker52]

from all MOBS just said... dont buy big headers they will hurt you more them help.... lol

 

[MOBS]

They'll be more of a waste also....the 88-95 engines are truck engines, they don't require high rpm's to reach their power band, thus not needing the flow capacity of large primary headers. The larger the primaries, the harder the fitment will be when installing(smaller piping fits thru more places than bigger piping), if I remember correctly, the exhaust port on these heads are 1sq.inch ports. My 454's headers were 2" and on dyno it lost about 3% of it's torque, so I ditched those premade things quickly but I'm still going to use their design as a mock up for making the long primaries for the 427. They fit extremely well and seemed to be in all the right places at the right times with very minimal numbers of bends. They're some $100 headers from ebay....got lucky with them, but they were the cheapo plated stainless headers that scratched and rusted. They would probably work ok with a port/polish job, cam, and long rockers....

Beware: single wall headers will get hot as all hell, especially if your engine tends to run on the lean side. I'd suggest exhaust wrap, which pretty much cuts out the reason to get chrome, plated, etc. Double wall chromies look pretty neat, especially if you HATE the look of the chrome turning colors. Single wall chromies will show you how hot they're getting by what color they change.

 

[Mr. 557]

So in my case, what ya'll are giving me the impression is that I wouldn't be benefitting much by using performance style headers and that I would probably be just as well off using either custom exhaust manifolds to upgrade to duals or a less expensive set of headers compatible with the stock truck engine?

 

[kevhill85]

So in my case, what ya'll are giving me the impression is that I wouldn't be benefitting much by using performance style headers and that I would probably be just as well off using either custom exhaust manifolds to upgrade to duals or a less expensive set of headers compatible with the stock truck engine?

The main problem with TBI motor is the the head do not flow very well.. A engine no matter the size is like a huge air pump.. The fast and smother the air enter and leaves the engine will detrain your hp/tq out put of said engine. That why the TBI engine reopened so well with vortech head installed..

 

[kevhill85]

So in my case, what ya'll are giving me the impression is that I wouldn't be benefitting much by using performance style headers and that I would probably be just as well off using either custom exhaust manifolds to upgrade to duals or a less expensive set of headers compatible with the stock truck engine?

When picking a header you have to figure out what rpm range you really want... Long tube header move the hp/tq up the power band. Where shorties keep the hp/tq lower In the power banded. For what you are looking for I would suggest shorties header so you will not lose any towing T/Q and this will be a big up grade as well from stock exhaust manifolds...

 

[Mr. 557]

When picking a header you have to figure out what rpm range you really want... Long tube header move the hp/tq up the power band. Where shorties keep the hp/tq lower In the power banded. For what you are looking for I would suggest shorties header so you will not lose any towing T/Q and this will be a big up grade as well from stock exhaust manifolds...

Today, I noticed that the exhaust leak seems to be primarily coming from the flange area where it connects to the crossover pipe. While I was underneath the vehicle though, it occurred to me that the 4 wheel drive stuff is inside the frame-well where the cat-muffler-exhaust would normally route in parallel with the exhaust system on the drivers' underside- How does this play out? I also don't want there to be any issues with the exhaust system being too low on the underside either. I DO want to make sure that I am clear on something: Long tube headers would benefit me more if I wanted more hp/tq higher in the band and shorties would benefit more in the lower range?

 

[MOBS]

Well, yes....but I always gauge it by what rpm the engine reaches it's power band at. Like a low rpm engine(one that reaches it's optimum power produced at lower rpm's) will have shorter primaries....in most cases, it's shorty headers. A high rpm engine(like a 9k rpm stock car engine) will have very long primaries....longtube headers, or sometimes just long primaries(collector hooks to tailpipe).

 

[kevhill85]

For clearance on the driverside I put an u in the crossmember . Not the best photos

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