Leathl_WS6

Thanks everyone for all of the great information.

Ill have to pull off a valve cover and check the casting numbers. If they are good ones do they still have to be ported or will they work the way they are and who should I have do the work? Bigger valves?

Also is the rpm a good mainfold for my application?

I'm clueless on what to do with the exhaust. I'll have to do some resarch on that.

Scott72

Check out Super Chevy magazine from last month. They have an article on oval port vs. rectangular port. I know it is a car magazine, but it had some interesting information in it. If you have large oval port heads, to make 450 hp, you will have to do some head work. There are some good prior posts on this if you do a little research. One I have printed out and refered to is "rec vs. Oval Port" from March of last year in the archives. As for exhaust, I spend more on CMI's because I run in Salt water and like the idea of having all stainless vs. aluminum, plus I have less of a chance of reversion running my cam vs an exhaust that dumps closer up the riser.. But as for exhaust, you'll get many opinions on this forum because everyone has there favorites. Remember too that your Risers/tailpipes will be different than a Bravo setup running TRS.

bobby daniels

Yes even if the heads are the good o49's you need to clean out the pockets and behind the valves ,ect. even some Lighting headers would help you ,,,,head work,,cam,,, headers and it would help alot then this winter put a 496 or 540 ect ,,in it with aluim AFR heads and good parts with a nice whipple or pro-charger ,and hang on

Leathl_WS6

Thanks Again guys.

Seems like I should look into exhaust and intake for now. Then over winter do the build up and head work.

I want to stay with a wet as noise is a problem where I live. Is there a fail safe spot for reversion? I'm not going very radical do you think that reversion is something I should worry about.

Any suggestions on a good wet exhaust keeping a somewhat lower budget in mind?

Also which intake will work for me now and also work when I rebuild over the winter.

Thanks Rob

Scott72

I hear good things about the Eldebrock Air Gap. I'm running a Merlin dual plain intake now, but will probably go with an Air gap next (I have to replace my aluminum intake every three seasons or so do to corrosion and salt water). As for exhaust, for something not radical a lot of people seem to like Stainless marine for the money. If you want to save money, you can go used and there is always some on the classified. I see a lot of Gils for sale relatively cheap. Just have them pressure tested to be sure if you go used.

Leathl_WS6

Can you tell me if these are any good for me. Will they work when I upgrade the motor to 450-500 hp. Or is there something better I could get for Similar money or a bit more.

http://www.offshoreonly.com/forums/s...threadid=52163

or these there 2 differnt onse in this link

http://www.offshoreonly.com/forums/s...threadid=51771

Thanks Rob

formula31

I run 781 heads too and they seem to be comparable to the 049's after work. If they dont have these valves in them, get them upgraded to 1.88 exhaust and 2.19 intakes at least. Also will need hardened seats installed on the exhausts. This exhaust systems you listed are nice but you should be able to find a set of gil manifolds for $500. Ive seen manifolds and pipes for as low as $750. Watch ebay too. Im in Huron, how close are you?

Scott72

Gil exhaust is fine, especially if your not running silent choice. I hear it dumps a little early with silent choice. You have to figure that Merc runs it on the HP500's. Remember though, you are running a TRS drive. Many times the tailpipes/Risers are going to be different than a Bravo. I would take mesurements and make sure that the Risers will work. I had to have my "tailpipes" custom made for my Formula because the standard Bravo pipes wouldn't work (CMI's). My buddy runs Stellings on his 40' Activator (running triple blown 350's - ex offshore boat). Almost like dry pipes - extremely loud. When we fired it up at the marina in Newport, RI, some guy almost fell in the water becuase he jumped. The Imco's are going to be loud too because of the length on the tailpipes I would think (could be wrong). I'm running around 500 HP out of my 454, I can list you the parts if you like.

Scott

Leathl_WS6

Thanks for the info.

I'm 20 miutes or so from Huron. I'm actually planning on running up to JP's on Sat for a early dinner if the weathers ok. I dock in Lorain at Beaver Park if you know where that is. Just the other side of Vermilion. Amherst is just South of Lorain.

Leathl_WS6

Scott that would be great.

I do need to keep it quiet or put some kind of silent choice on it. I'll look for a set of gil mainfolds. If I need to have pipes custom made who does that.

I think I'm going to try the RPM Air Gap. Just wondering if that gap would really make a differance being in a closed compartment?