Re: Parts questions

Posted by HH56 On 2023/3/13 10:57:50

Others will surely have better answers but here are a few things I can think of that might need to be compared carefully.

The 356 engine and trans is overall a much heavier duty combination. As I recall the 356 trans has a 5th mounting bolt at bottom center which I do not believe the 288 has. I think the 2 bolt locations on each side into the bellhousing are the same on both trans but make sure the spacing is the same on the bellhousings to ensure the smaller trans will bolt on. While the bellhousings just bolt onto the blocks, because the blocks are quite different the hole spacing may not be the same. Nevertheless you may want to see if the entire bellhousings will swap. If they will bolt on the block then check the length as the 288 bellhousing may be different which might throw off the locations of the transmission mounts. The output flange and U joints may also be different which will mean some changes to the driveshaft in addition to any length differences.

Check the bolt hole locations for the motor mounts on the side of the trans cases. I believe transmissions made after 48 have two sets of mounting bolt holes per side that are a couple of inches apart but if there is only one set of holes verify the location is the same distance from the bellhousing on both transmissions. If not or you have a difference in bellhousing length there will probably need to be crossmember or frame modifications.

The 356 flywheel has a larger pilot bore and bearing for the larger diameter trans input shaft so that is something that needs to be taken into account on the smaller trans as well as the pressure plate bolt spacing on the flywheel. The smaller clutch and pressure plate diameter on the 288 may not bolt to the larger 356 flywheel and the smaller flywheel may not bolt to the larger 356 crankshaft. Careful comparisons and measurements need to be done. The throwout bearing, fork and carrier on the 356 is also larger because of the larger input shaft. You will probably need to figure out if you can swap the entire fork and throwout bearing carrier assemblies unless you can swap the entire bellhousings. Also remember the small retracting spring for the throwout assy. It is held at the bellhousing end by a small pin thru a hole in the bellhousing. That pin is kept from falling out by the trans pushing against it and may have already been lost when the trans and bellhousings were separated. A standard 3/16 x 1/2 inch long clevis pin can be used as a replacement but that may not be easily found in France.

If the trans has an overdrive, the 356 will probably have a heavy duty version of the R9 overdrive while the 288 trans will have an R11 overdrive. Unlike the R9, I believe there was only one version of the R11 overdrive so the higher torque in the 356 will not be an issue but the electrical operation and components are completely different. In addition to the 288 trans/OD you will need all the overdrive electrical components in the parts car transferred over. The lockout lever is on opposite sides of the overdrives so the cable mounting in the car needs to change location too.

Anyway, just a few things I can think of offhand to check and am sure there are more. Maybe someone else can add to the list.