1974 Chrysler 75HP - gearbox & lower unit swap

[Screaming kiwi]

Hi,

The gearbox on my '74 HP crunched the other day - don't know extent of damage but it is not working and the oil has a lot of metal in it. I can get a later model one piece unit off a 85HP Chrysler and wondering if it will fit. If it does, will the water pump/impeller be the same?

Thanks,

 

[Frank Acampora]

Re: 1974 Chrysler 75HP - gearbox & lower unit swap

If they are both two piece lower units with a splined shaft and pin through the prop hub, then either will fit--even if they appear different. Earlier and later two piece lower units simply had a different upper casting. Everything else is the same.

The one piece lower unitwas designed around 1978 and is completely different. It will not fit. It can not be modified to fit either. Sorry!

You need to look for a two piece lower earlier than 1978.

HOWEVER: If you can also get the midleg to the one piece lower unit, then you can swap everything onto it and have the much better performing engine with a better selection of props.

 

[Screaming kiwi]

Re: 1974 Chrysler 75HP - gearbox & lower unit swap

Thanks Frank, I appreciate that. I've got another gearbox with a damaged fin (skeg?) so I will see if I can find someone to swap the gears over, I'll keep a look out for the later model mid-leg to. I'm realising when owning a Chrysler it is like having an odd Aunty in the family - she is a bit of a nuisance at times but we love her all the same.