ha! i was wanting to put a new exaust system on my 1991 firebird and i hear a lot of talk about long and short headers ,x pipes and y pipes ! what is the best way to for gas mileage ,and power?

 

long headers are good for gas economy,and the short once are good for power and noise.i think its better to make the rear part operating with a simple quick fit system.

 

i have a question about afr heads.i am building a chevy 406 motor and i want afr 210 heads,but the suplier told me that the plugs are not straight.is there a big diffrence between the straight and the angled plugs.?

 

what are you talking about? thats all wrong

Long headers are for high rpm performance and exhaust scavenging, they have bad ground clearance on these cars and are not emissions legal. Generally these are race only parts.

shorties fit in the stock location, are a massive improvement over stock and work very well for upwards of 500 horsepower, more than enough for most cars. They also offer much better ground clearance and can be had in emissions legal setups.
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It is done in this case because of relocated vavle locations in the heads.
sometimes headers clearance issues arise with angle plug heads, but not always. It depends a lot on what headers you are using.

 

ok! so what i am hearing is that for a stock motor i need to run short headers and a y- pipe. For big hp you need long headers and straight exaust,wright?

 

thats pretty much the case, In these cars for he most part, its not worth the aggravation trying to use LT headers on a street car. They hang too low, making a y-pipe is difficult, and they are not emissions/street legal.

 

This advice is right on. Also on a stock engine, the power increase of long tubes vs short tubes is less significant, and with any modern cat converter, you will see zero power loss over no cat. We have smog-legal 350 CID cars here in CA putting out 325 HP to the wheels with shorties and single cats. Your stock 350 put out about 190 on a good day to the rear wheels stock.

TA