Perfomance advantage High flow manifolds (stock) or "shorty" style headers?

[bigred68]

 Can you guys tell me what, if any performance difference there is between stock (hi flow) exhaust manifols, or "shorty" style headers? My father-inlaw is building a street rod and standard long tube headers won't fit and he has a set of hp mainifolds. Is the cost of shorty headers worth the gain?

[firefighter3931]

Can you guys tell me what, if any performance difference there is between stock (hi flow) exhaust manifols, or "shorty" style headers? My father-inlaw is building a street rod and standard long tube headers won't fit and he has a set of hp mainifolds. Is the cost of shorty headers worth the gain?

I would say no....not worth the expense. The key to making manifolds work well is the cam profile. Something with a wider LSA will reduce overlap and help with cylinder scavenging. That's the key to making power with a restrictive exhaust system. 



Ron

[bigred68]

Thanks!!!

[Mike DC]

You might wanna look into Tri-Ys before abandoning the possibility of headers entirely.  Like maybe those ones the Schmacher sells for big block wedges. 

[Musicman]

Tri-Y's are a nice alternative, but if you already have a set of HP's in hand it would be hard to justify the extra $725 + 
There will be a performance gain, but is it worth the extra cash   
If you were starting from stock then I would say Yes, go look into it  but....