New 5.7 exhaust manifolds on a 1981 engine

[dnsellers]

I have just finished building a replacement motor for a 1981 Sea Ray. I was told when replacing the exhaust manifolds, to swap the standard rear rise manifolds with the newer center rise. Evidently the exiting air flow is more equal giving a bit more efficiency and power, and the bolt patterns are supposed to be the same. Just some minor plumbing to the old y-pipe for the exhaust. Any comments or suggestions?? Thanks!!!

 

[dnsellers]

Re: New 5.7 exhaust manifolds on a 1981 engine

Anything?? Anybody??

 

[Bondo]

Re: New 5.7 exhaust manifolds on a 1981 engine

NAPA Part # AP 5499,.... <br />Is a Complete Conversion kit to do as You Wish.......

 

[AaronG]

Re: New 5.7 exhaust manifolds on a 1981 engine

For what its worth, I'm pretty sure the center rise manifolds are less expensive, and since they are so common, they should be easier to find on a saturday afternoon. (as opposed to not finding the part and having a weekend ruined.)

 

[dnsellers]

Re: New 5.7 exhaust manifolds on a 1981 engine

Thanks for the info.. I couldnt find that NAPA part tho...where should I go for it?? Anyone done this conversion, pros/cons...I guess I just have to run some type of flexible exhaust tubing to the old y-pipe...ANy other suggestions??? This seems like a pretty common conversion. Thanks again.

 

[KaGee]

Re: New 5.7 exhaust manifolds on a 1981 engine

Make sure you got your ducks in a row. It can get costly if you make a mistake.

 

[Beachcraft-24]

Re: New 5.7 exhaust manifolds on a 1981 engine

DEREK I did this swap on my 1978 with a 255 v8 & volvo outdrive last year. they make adapter to hook up to the old Y pipe. the riser&adapter are 3" so be careful what you are buy later years are larger.not sure what year they changed.if you need part# i can look back in file and get them for you.