I am trying to find out what the measurement is from the motor side of bell housing to the transmission shaft. 1-1/4"?
I need this because I am using a ZF 85A transmission to a BBC so it needs to be the same as any other Merc style bell to transmission. If I need spacers I can order them.

So your looking for the measurement from the face of the mating surface between the engine and the bellhousing, to the front surface of the input shaft of the transmission with the transmission bolted to the bellhousing? Is this correct? I have Huber 925 transmissions (similar to Velvet drive), and bellhousings which are top mount starter, designed for rear mount plate installation, here at the shop. I can mock up and measure whatever dimension you need but I would like some clarification, and please determine if the dimensions from this combination will give you what you are looking for. Thanks.

Can't give you a measurement right now but I can tell you some input shafts go into the flange which the flywheel mounts to on the crankshaft and use a pilot bushing in that flange to support the input shaft. Have no idea how long the input shaft is on the trans you plan to use. Sounds like you need the bellhousing and drive plate which is used with that particular trans for a chevy.

Can you bolt up the drive plate to the flywheel and measure how far out the splined coupler on the drive plate is from the block ? This should tell you the dimension your looking for.
Or don't you have the bellhousings or drive plates yet.

I have attached a photo of the measurement I am looking for.

Thanks

Thats what thought, I'll get it for you today. Mine will be a Mercruiser top mount starter bellhousing, and a Huber 925 transmission. The beelhousing is designed for a 1/4" rear plate engine mount, between the bellhousing and the engine. Thanks.

Are your bellhousings notched for the engine Plate? I will have a rear mount plate also. However the bellhousing i am looking at is flat on the engine side.
Thanks

Most Mercruiser bellhousings are designed to compensate for the rear engine mounting plate with a thickness of 1/4". The face of the bellhousing is flat and mounts to the rear mount plate that is sandwiched between the block and the bellhousing. I mention this because if your rear mount is thicker, the dimensions change. The dimension you requested per your picture on my set-up is 1 1/2 inches. This is from the engine side face of the bellhousing to the front edge of the input shaft. Some other reference numbers are - Total depth of bellhousing, face to face of transmission mount surface is 4 1/16". The input shaft of the Huber 925 protrudes 2 9/16" from the transmission mount flange surface. The engines has a Callies crankshaft but I did measure that I have 4" clear into the coupler plate from the rear bellhousing flange. This was going into the crankshaft end, but the area was machined into the rear flange of the crankshaft. In other words the input shaft could protrude into the coupler a maximum of 4" before any interference, not just the 2 9/16". I suspect most crankshafts are machined this way. If you need to make a spacer be very careful to reproduce the index flange found on the front of the transmission and provide a female version of the index ring in the spacer - copy the bellhousing flange. The transmission bolts to the bellhousing with bolts but it's location and centerline are determined by the index flange. PM or call me if I have you completely confused. Good luck with the project.

Thats great. I guess I will not need a spacer since I'm already 1/4" shorter. Thank you

Your input shaft actually extends 1/4" further in the coupler, I see no problem with that. Good luck.