75 Holiday Repower

[STARCRAFT75]

Hello all, new poster here , but long time follower .
I have a 1975 Starcraft Holiday , 140 HP Mercruiser with an MC 1 drive. 22 ft long
It has served me well for many years . But it is time for a rebuild . Floors,transom,motor.
I have a line on a donor boat with a 4.3 liter v6 alpha one drive.
Question is would I gain an substantial increase in power and speed with the v6 or would the additional weight offset the gain.
I imagine this Boat was originally offered with a straight 6 ? That was my next option possibly?
Thank you for this informative site and great peoples who offer help.

 

[Scott06]

Hello all, new poster here , but long time follower .
I have a 1975 Starcraft Holiday , 140 HP Mercruiser with an MC 1 drive. 22 ft long
It has served me well for many years . But it is time for a rebuild . Floors,transom,motor.
I have a line on a donor boat with a 4.3 liter v6 alpha one drive.
Question is would I gain an substantial increase in power and speed with the v6 or would the additional weight offset the gain.
I imagine this Boat was originally offered with a straight 6 ? That was my next option possibly?
Thank you for this informative site and great peoples who offer help.

I think you will see a noticeable difference in power. Im not sure whatyour expectations are but at 22 ft you could go the next step up to a 5.7 If you really want it to be quick.
what year is the 4.3? 96 and later is the votecs and should be good for 220 hp Witha 4 bbl carb

 

[STARCRAFT75]

The 4.3 is a 93 . I could get up near 30 Mph with just myself aboard with the 4 banger , but with Six of us I topped out around 25 .
Not looking for a speed demon just a little more power.
Can anyone tell me the weight difference between my 4 cylinder and the v
V6 . it is a big boat 22 ft but I thought a v8 would be way to heavy ?
Got me thinking though a 8 cylinder sure would sound nice and get me there quickly.

 

[Bondo]

Ayuh,...... I had a '74 221 S/C Islander, 'n pulled the 120 hp/MC-1 , 'n dropped in a '94 4.3LX/ Alpha 1, then ran it for over 20 years,.....

With the 4 banger it did 'bout 28 mph, but never 30 mph,......
With the 4.3LX it pulled a consistent 43 mph, with of course, neck breakin' acceleration,....

I think you'd be very happy with yer swap,.....

 

[Scott06]

The 4.3 is a 93 . I could get up near 30 Mph with just myself aboard with the 4 banger , but with Six of us I topped out around 25 .
Not looking for a speed demon just a little more power.
Can anyone tell me the weight difference between my 4 cylinder and the v
V6 . it is a big boat 22 ft but I thought a v8 would be way to heavy ?
Got me thinking though a 8 cylinder sure would sound nice and get me there quickly.

Sounds like with your comments here and the performance numbers Bobdo shared, your plan of putting the 4.3 in will meet your needs well.

 

[STARCRAFT75]

Ok next question. The donor boat will com complete with outdrive and all.
When I redo the transom is the keyhole cut out the same from the old MC1 drive as the newer 93 alpha 1 drive?

 

[matt167]

Ok next question. The donor boat will com complete with outdrive and all.
When I redo the transom is the keyhole cut out the same from the old MC1 drive as the newer 93 alpha 1 drive?

the keyhole is basically the same even on Alpha Gen II. Slightly different

 

[Bondo]

Ok next question. The donor boat will com complete with outdrive and all.
When I redo the transom is the keyhole cut out the same from the old MC1 drive as the newer 93 alpha 1 drive?

Ayuh,..... You'll need to drill 2 new holes up near the top, 'n possibly tune the tiller arm slot slightly,.....
Really, no big deal,......

I use the fiberglass skin from the donor hull to locate the new holes,......

 

[STARCRAFT75]

Decided to go ahead with this project.
Getting the boat out of storage in the next few weeks.
Picking up the donor boat this weekend.
Then time to tear in. Sure I will have lots of questions .
Trying to decide now if I want to redo the interior back to stock configuration
Or something custom.

 

[Bondo]

Trying to decide now if I want to redo the interior back to stock configuration
Or something custom.

Ayuh,.... Make it Yer boat,.....