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-   -   365hp 454 mag (https://www.offshoreonly.com/forums/general-boating-discussion/325780-365hp-454-mag.html)

Nova Rob 05-01-2015 10:36 PM

365hp 454 mag
 
Hi! New to the site , i purchased a 87 wellcraft nova spyder for my 54th birthday, receipts show the 330hp was replaced in 01 with a 365hp mill the boat has a single
With stern drive exaust, guite. You can hear duration in the cam but that's it sounds like a sewing machine. I have read the 365hp had the better stuff. Solid lifter, steel crank, rect heads 4 bolt mains true? ? I'm used to 440 mopars with big flat tappits, valve adjustments constantly allways noisy, granted more rpm, more lift, help me GM guys.

mike tkach 05-01-2015 10:40 PM

the 365 mag is a good engine,all forged internals.it came with a hyd flat tappet camshaft.

14 apache 05-01-2015 11:24 PM

Very good engine. I had 370hp engines in my boat think only difference was roller rockers.

iliveonanisland 05-02-2015 03:44 PM

Ģo with what u know, impress your pals, stick a hopped up 318 mopar in That badboy...

dereknkathy 05-03-2015 06:54 AM

very sturdy engine. detuned a little so it lasted the warranty. the 365 is at-the-prop hp. in truth it is around 400-410 if you dropped it in a dyno. the motor would like more cam, but the exhaust manifolds won't. 87 Nova. so it is an alpha drive? be nice to that drive. they stopped using the TRS in 86. didn't have the bravo ready to go until 88. so they had to use the alpha with 454's in 87. they ALSO called the 330 a magnum in 87, so you need to do some checking to see what engine you really have. most obvious check. iron low-rise intake? (carb flange below valve cover bolts) or aluminum hi-rise? (carb flange approximately level with top of valve covers.) but either way, that engine is too much for that drive. it can easily snap the vert shaft if you go full throttle from idle like it is a dragster.

Nova Rob 05-03-2015 09:08 AM

Thanks for all the feedback, I suspect the short block was replaced it has the 330 tappet covers on it, the work order said cracked block. It has performer intake & edelbrock carb, I am going to replace the carb with a holly 650cfm vacume secondairys. It has the alpha drive so no holeshots. Am I correct to think that everything in the transom must be replaced to change to bravo drive? At any rate I will be nice with what I have for now.

Griff 05-03-2015 01:00 PM

You need at least 750cfm and mech secondaries work better on a boat.
Nothing wrong with Edelbrock carbs if its set up right and the right cfm.

iliveonanisland 05-03-2015 01:06 PM


Originally Posted by Griff (Post 4299742)
You need at least 750cfm and mech secondaries work better on a boat.
Nothing wrong with Edelbrock carbs if its set up right and the right cfm.

ebay that edelbrock, get a reworked/pro series holley, 750cfm works great on a 454

Nova Rob 05-03-2015 05:57 PM

If boats like mech seconaries, I'm in luck i have several to pick from on hand. I never could get a Edelbrock to do what I wanted it to. Thanks guys.

Powerquest230 05-03-2015 06:08 PM

The Edelbrock carb will work just fine on that motor unless you upgrade cam and exhaust. If IRC their model #1410 was intended to be a replacement for the Carter that came on the mag.


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