TRS drive and small block
 

Hi all
i am after some info/advise on a ski boat set up i have in the making
So far i have searched and read about 50 post on the TRS drives and what they are capable of but cant find what im looking for.
What i have is a hains 1800so ski racer with a 454 and TRS drive and what i would like to do is change out the big block for a small block chevy. what i cant find is if the small block will mate up to the gear box, are they the same bolt pattern . will the trs drain to much power from the motor and/or can i do away with the trany all together and just shift into gear with the motor turned off then fire it up to go. I have brought the motor and drive as a package for $5000 here in oz and not real keen to run the 454 cause i want to run a back seat.

any help would be great from you blokes in mercury land..

i think the bolt patern is the same but not sure.

You need to keep the trany. There is no shifting in the drive at all. If you want to move things back and you have a Borge Warner transmision then see if you can find a Merc trans. That will move things back quite a bit.

Yes the small block will bolt right up. In the mid '70's this package was availiable with the 350 cu.in. smallblock. As far as space saving though the small block is only 1 3/4 inches shorter that the big block.

No you can't do away with the tranny. The tail housing of the tranny supports the input shaft of the TRS drive and with the Merc Trans ll transmission the tail housing also supports the rear of the engine.

The TRS was availiable with 2 different transmissions. The Merc Trans ll and the Borg-Warner. The Merc Trans ll being 9 inches shorter and having an aluminum case was about 50 lbs. lighter. The Merc Trans ll the tranny and bellhousing are all one piece. Borg-Warner has a seperate bell housing.

So if you have a Borg Warner tranny and switch to the Merc Trans ll and a small block all you will pick up is 10 3/4 inches.

you could use a crash box style trans .

thanks for the info guys its a great help.
i take it the merc box should hold up to the big block no worrys in a smaller/lighter boat than big bangers you run over there. that being that the small block is only 1 3/4 inches shorter so might aswell run the 454. is there a big weight difference between the two engines? maybe loose the big cast merc manifolds to shed some pounds

So if I want to put a big block Chevy in my Baron instead of the 350 that's in it, it will bolt right up no problem?

Do the parts swap right over with no issues or will I need something?

Depends on what "parts" you want to swap over. The motor mounts, yes. Bell-housing, coupler, trans yes. the sea water pump you can reuse as well....there's a few other items you can reuse like the distributor and the alt and carb but the rest would need to be motor specific

Thanks for responding wally. Sounds like I can use all those parts to swap over then. It's a gen 6 motor. 400 hp .

Will I need a different flywheel than the toothed thin version? Or is the stock one for a big block fine?