OK so I bought a Nordic heat with no power or drive.
Having trouble deciding weather to put blue motor EFI or say screw it and put in N/A motor.
EFI motors are nice had them before but I can get more motor for the buck. What do you guys think?

How about a FAST or holley EFI setup as opposed to a factory merc EFI package?
Stand alone DDC control and some minor fuel system mods make it easy.

well that's just it, I don't really know much about putting in fuel inj..comp and me don't get along . I can barley turn the dam thing on.lol

What's your speed goals?

496's 64-66 mph, 500efi 68-72mph, 525efi 74-77mph, 575sc 80-82mph, it takes big big power to start running faster! 800hp to run 90mph and 1000hp to break 100mph. My 525efi XR drive, 1" spacer and stock 26 bravo is 75-77mph.

Yup and the 496s are turds IMO, especially with a few people on board.

A blue motor 525 will likely be the best option for future resale value if that holds any weight in your decision.

Tim on here has a big NA motor, 588 something or other and runs upper 80's. It's an impressive package.

looking at a 525efi and a 500efi with whipple. 500efi is more power but how is reliability

On a hot humid day, 3 passengers, a couple coolers and junk, I was lucky to hit 60. And I find the 64-66 quoted by Dirty D as achievable but only under good circumstances; one passenger, less than full tank, not much junk on board, cooler day, a bit of chop.

I hit 67 once, low fuel, one person, with the tide/current, cool day, with the wind, never duplicated.

Mine has a 525. On Havasu with about 25 gallons of fuel, two people, and nothing else in the boat we hit 76. I boat on Powell which is 3600-3700 feet. With 4-6 people, lots of beer and all the typical **** in the boat I top out at about 67-68. I did add a 1" spacer after the Havasu run. When I put it on my local lake which is 4500' planing was slow. The spacer helped a lot as many of the Heats were built with too high of an X dimension.