Well the 502 MPI is only 415 at the drive and it did 72 when I first got it. But after adding drive showers and the advent of ethanol fuel (both the same summer) I lost a couple. And I have not gotten the props right with the 500s. Although it does seem like you have to throw a huge amount of power at them to get anything close to 80.

boat would hit 73 on gps with me and half tank of fuel.looking to get 76 to 78 we will see

http://www.valakoraceheads.com/

thank you!!

That sounds as an impressive speed to me with this setup, very nice.
Until the end of last year I have been running my 1989 311 SR1 with stock 454MAG's (365HP each) and bravo drives, stock mirage plus 23p and I was seeing 65MPH on GPS.
It surprises me that 2 x 415HP with TRS will give you 8mph more.
I have repowered with HP500's and I ordered a set of bravo 1 26P props at BBlades. Let's see where these will get me next month. With respect to the EFI, it is comparable with Ted's 311.

What is weird about these boats is the wide range of weight. My boat sits MUCH higher in the water then my buddies. His exhaust tips are just above the water. Mine are a good 4 or 5 inches over the water as I recall.

Paul I think what Ted stated earlier is that the 420's are rated at the prop not the crank like the 365hp motors are. So it is probably a 6-7% additional advantage.

Well, the difference in a full or emty tank is already close to 3 inches if I am right. I didn't know that there was so much variation in weight although I can imagine that various types of engines will differ something in weight and maybe TRS or Bravo will differ as well. Exhaust tips of my boat are also about 4-5 inches above the water with a half tank of gas.

So, are all 420's specified at the propshaft?

I always thought the older engines, like the 454/420, 454/365, etc, were rated at the crank. I think that is why the 454/365 got relabed the 350HP engine in the mid 90's.

I agree that is a great number for TRS. i think it is gonna take at least 600 hp a side to get a TRS boat to run 80.

didn't OFFTHEFRONTS boat run like 78 with 496's and bravos?

Yes, Offthefront had 600hp a side and his boat did about 78.
His engines were custom build if I recall well..