phragle

iTrader: (3)

You need to read more.

Not trying to dog you, just trying to save you pain and frustration.

Stock 7.4 peanut port heads suck. The 7.4 has little rods and a cast crank... generally fine for a 400 hp na motor, but if they need any work your already upside down. You screw up marine clearances, oil system, cam selection etc...Go directly to start over, do not pass go, do not collect 200 dollars.

Find yourself a nice low hour mag motor and be happy while you figure out marine motors. That will give you a good base to grow.

Actually given your boat, get a fresh stock mag and leave it alone. If you have the deep bravo 2 lower, maybe replace it with a standard lower and enjoy the boat for what it is, Your wallet will be happier, your wife will be happier and you will be happier.

jekyl

Just build it back stock .there is no speed gain with more power on that hull.That's what I recommend,fix it enjoy it. Really.

cdre

Phragle, you got me with my wife being happier... She already scowls everytime she sees me on a boat website... Stock it is... although, since I already have to buy a full exhaust, any advantage to a stainless through prop? Should pay for itself by me not having toreplace it in 5 years...

getrdunn

iTrader: (7)

I think your getting the idea. Possibilities are endless however without spending some big bucks performance gain will be minimal. I did the 454/330 on roids a few different times with great success however it involved swapping out to mag Pistons, Ported 265 oval port darts, torker 2 intake, Holley 800 cfm carb, 502/465 hp cam, lightening headers, heads decked to get 9.6:1 comp. Package is reliable and makes 480 plus hp.

Just keep in mind it takes 13-15hp to see 1 mph gain on average. Your advice on rebuilding to stock or finding a fresh 365 mag is probably your best route without monies getting out of hand.

distantthunder

I started out with the idea of a "budget rebuild", Ended up with a completely different engine and frustrations. I am finally enjoying the fruits of my labor but if I were to do it all again, I would have bought an assembled long block and called it a day. My .02

88Rocket

I just did this . now mind you I have 2 automotive big blocks in cars so I had a bunch of parts laying around. but I picked up a 88 sensation rocket they guy I got it from well lets just say wasn't nice to the motor 7 of the 8 rods were seized to give you an idea when I broke down the motor I had to use a bar 4 ft long to move everything enough to get eh nuts off the caps to remove the rotating assembly. so what I did was called around and got nothing but 2500+ prices for motors so instead I sent it all out to a machine shop to be checked Block was ok needed a .030 over bore everything else was fine crank went .010 .010 hot tanked the block new freeze plugs cam bearing and all they reworked my rods and put them on new pistons with new arp rod bolts. all said and done 1700.00 for a fresh short block. peanut port heads nope not going there had a set of 049 oval ports laying around on they went. had an dual plane edelbrock intake laying around on it went. went back to the cmi split tube dry headers. didn't like the Mallory distributor so I went with a DUI hei started off with a 650 holley didn't like it now I have a flowed and jetted 850 that's up to 930 it runs good but alittle fat Monday it's going into Merlin marine to figure out which carb will be better and get tuned Not my strong suit. all in all I have the 1700 plus spare parts I figure its pushing 425-450 now . it's not hard to rebuild an engine. part selection is key tho. Here's a video of it running on a hose. we were adjusting the timing at the time.
https://www.youtube.com/watch?v=iQT_KtSgEZk

a photo of the motor as I was putting the boat back together.

88Rocket

video where you can hear the cam.

https://www.youtube.com/watch?v=SykhV01AuL4