what are the speeds outta 312 with 454/310's mpi's 454/mags 385 efi's i believe and with 502's?

I had a 312 with 502's. Saw 74 GPS a couple times but 71-72 most any day. 454/385's should be 2 mph slower while the 454/310's will likely be 65 under the best of conditions (probably a little slower).

a friend just traded his in at shoegrens,the boat did like stated with the 310 efi's 65mph,,saw 67 once with no fuel..with the 5 blade maximus props the fastest was 62 mph but would plane out and stay at 2100 rpm's at 20 mph..

what else can you tell me about this one, thats the one I'm looking at

Is that the one on Shogren's website now? Thought those were the 385HP mags.

Mercury made 454 MPI's and 454 Magnums. Those are MPI motors......completely different and not suited for upgrades either. They make 310hp.

I have the 454mag mpi's 385 hp, 70mph on the GPS. Great boat but does not like to go slow. If you want to go 25 mph, drives must be tucked in and you must use some tabs. My only suggestion is to look for a boat with full hydraulic steering and the big merc tabs. You will have no regrets.

good numbers I'd like to have

the boat was lift kept,,stayed in the water only on the weekends thenput up in a warehouse..winter it was kept in the same warehouse and is heated...the 5 blade props that were on the boat are available..the guy that owned it changed the oil in the engines every 30 hours with mobile one 15w50. the drives were just servised,,he also still has the silent thunder platform which he wants to sell...

I have a 97 312 with 454 mag mpi's I added offshore exhaust ditched the silent thunder, and added a vortech breather.. I run 72-73 on GPS.. however my prop slip on my Bravo-1 30's are at 17% I think if I could get the slip down may paick up a mph or 2. RPM is 5100-5200 ( had the ECU bumped a little too)