Worthwhile 7.4 MPI upgrades

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10-07-2007, 07:42 AM

#11

Payton

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Quote:

Originally Posted by wet_rat

You may have a good point. I guess I am looking for some of the cheaper (is there such a thing in the marine world?) upgrades to better enhance what is there. I would think that finding a couple used intakes and heads with new cams and ignition upgrades ($4K?) should yield good results for the $. Selling the two motors and purchasing two more would certainly cost 3-4x that, atleast. Am I too optomistic in my thoughts?

You had better add $1000-2000 per engine for a better exhaust system or the other mods you are talking about will be severly choked off.

10-07-2007, 12:55 PM

#12

Donman

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Quote:

Originally Posted by wet_rat

I think I already have reliability and all that can be expected from economy and twins, so I guess speed. I would love for mine to have a stronger sound, maybe a little more lope.

Here`s what you do :

Those engines already have pretty decent heads for a sub-5000 rpm engine. The Vortech heads flow ok and have large oval ports. Keep the heads and upgrade the cam. You have a low-lift hyd roller cam now. You can keep the non-adjustable valvetrain and use the oem lifters if you stay under .540 lift. Get matching valve springs. You will either need to modify the ecm or swap to a carb. I say go carb. You don`t need MSD ignition. Your existing Delco Voyager ignition will work fine.

$1500 per engine will give you a boost in hp and a meaner idle.