454 to 5.7

[d-reed]

New to the boating world. I am however a Ford Certified Tech. I have a 96 Sundancer 250. I am wondering what is involved with swapping out my Gen 6 454 with a complete drop in 5.7 MPI unit? I know that I may have to change the steering rack because the fittings on the hoses are not the same. How about the mounts and all the cable brackets and things like that? I am pretty sure the wiring harness plug is the same?

If anyone has done this swap please let me know what's involved.

The only reason for the swap is because my 454 is no good and I have access to this 5.7

Thanks, Dan

 

[Creekwood]

Can't help with the technical, but you will be decreasing the value of your boat by more than the savings you will get I think. Boats with base engines are much harder to sell. If you got the 5.7 for free maybe it would be worth it, but you may still be better off selling the 5.7 and using the money to fund the cost of a new or rebuilt big block.

 

[techmitch]

I wouldn't do it even if I got the 5.7 for free.

 

[MonacoMike]

New to the boating world. I am however a Ford Certified Tech. I have a 96 Sundancer 250. I am wondering what is involved with swapping out my Gen 6 454 with a complete drop in 5.7 MPI unit? I know that I may have to change the steering rack because the fittings on the hoses are not the same. How about the mounts and all the cable brackets and things like that? I am pretty sure the wiring harness plug is the same?

If anyone has done this swap please let me know what's involved.

The only reason for the swap is because my 454 is no good and I have access to this 5.7

Thanks, Dan

Welcome aboard!

You do not need to post the same question multiple times, most of us use the recent post or new posts to see all the current posts.

MM

 

[d-reed]

Can't help with the technical, but you will be decreasing the value of your boat by more than the savings you will get I think. Boats with base engines are much harder to sell. If you got the 5.7 for free maybe it would be worth it, but you may still be better off selling the 5.7 and using the money to fund the cost of a new or rebuilt big block.

Never thought of it that way, I would think that going to fuel injection would be a good upgrade. I liked the idea of easy starting, better fuel millage, and the easier access to drain hoses for winterizing. I have an engine builder who has a nice remanufactured 454 Gen6 that he will set up with my carb, ignition, and oiling system that he will run on his dyno and do a few pulls to make sure it's tuned right. It's a few more bucks but it would be back to stock.

 

[d-reed]

Welcome aboard!

You do not need to post the same question multiple times, most of us use the recent post or new posts to see all the current posts.

MM

thanks!

 

[Lazy Daze]

I'm going to take a different stance on this one. We're only dealing with a 25' boat here. And, given that it's almost a quarter of a century old, I really don't think resale is going to be affected much. Meaning, it could sell very easily with a new era small block with the multiport fuel injection. That last part could definitely be an advantage - along with the engine, itself, being much newer. That's not to say that having a big block in that boat wouldn't be good for resale, either. It certainly would. But I think there are PLENTY of people out there that would be happy to buy that boat with an MPI small block... and, quite honestly, I think there are plenty people out there that either (1) wouldn't care or (2) don't know enough about engines to care. I ran a larger DA with an EFI small block for about 7 or 8 seasons and was VERY happy with it - even doing watersports with it. It did have a B3, so that certainly helped, but it was also 1,000lbs heavier. In the end, I think you'd be just fine with either engine - both have their merits and I don't think you'd be affecting resale going either way.

To answer your fitment question, though... I'm not sure. I've never done a small block to big block (or vice versa) swap.

 

[Quint4]

Ditto what Lazy said.

 

[Lazy Daze]

Oh... in regards to your fitment question... You can get the measurements for the motor mounts from the 454 since you have that setup. There are plenty of boats around with small blocks - whether it's a 305 or a 350 won't matter. Find a boat that has decent bilge access and ask nicely.

Just thought of something else... Try contacting Sea Ray and ask them for some help on this. Explain the situation and see if they have any old files that show part numbers for Merc motor mounts and/or whatever Sea Ray designed to receive the mounts. Often the mounts are simply lagged down onto the stringers, but other times something like a certain size aluminum L-channel is used.