The 'E' Type Forum

I have a 1964 3.8 fhc that has, in the past, been fitted with a 4.2 and all synchro box. I'm seriously thinking of fitting a 3.8 RAxxxx and Moss box.

Do people tend to feel that this is a good move both from a drivability and increase in value points of view.

Having driven a 3.8 with a moss box I would have to say that the later jag box is a distinct improvement. Fitting a moss box won't improve driveability. My 3.8 has a later box and my moss box adorns the garage As to value....unless you have the original box that came with the car new...matching numbers and that jazz....I can't see a moss box enhancing value much either...just my opinion...

Before you make changes see if you can go for a drive in a 3.8 with Moss box. Both the engine and gearbox are quite different from the 4.2.

So it would be much better to install a 3.8 RAxxx engine but keep with the all synchro box as they're a much better drive?

I have a 3.8 and swapped to a later box. I love it.
In my opinion changing the 3.8 to 4.2 wont change much if anything. It all depends on what you are trying to achieve. As a matter of interest what cylinder head and inlet manifold combination is currently fitted and also the brake system (bellows or remote servo) ?
If you want to return the car to as near orig as possible firstly buy the Eype originality book and look at the extent of what you might want.

An alternative approach is to collect all the orig components and either make the decision later or when it come time to sell offer it with the bits.
As I said just My opinion.

phil.dobson@mac.com wrote: ↑

Wed Nov 28, 2018 8:39 am

I have a 3.8 and swapped to a later box. I love it.
In my opinion changing the 3.8 to 4.2 wont change much if anything. It all depends on what you are trying to achieve. As a matter of interest what cylinder head and inlet manifold combination is currently fitted and also the brake system (bellows or remote servo) ?
If you want to return the car to as near orig as possible firstly buy the Eype originality book and look at the extent of what you might want.

An alternative approach is to collect all the orig components and either make the decision later or when it come time to sell offer it with the bits.
As I said just My opinion.

Hi Phil,
I'll be swapping the current 4.2 (8xxxx series engine .... not sure what it's out of) back to a 3.8 RAxxx. I've no idea on the cylinder head / inlet manifold it has at the moment but it has the bellows servo.
Cheers D

As suggested above, swapping a synchro box for a moss won't improve driveability - quite the opposite from what I understand. Similarly, I can't imagine that swapping the increased-torque 4.2 for a 3.8 would aid driving. As to value, I have no idea. However, whereas the originality of matching numbers helps value, can't see that a wrong-number 3.8 would be any better than a wrong-engine 4.2. Just my views, not based on any experience!

I would not dissuade you from reverting to a 3.8 engine, which is less torquey but more revvable than the 4.2 , but I would be strongly against changing the ( presumably EJ ) box , which was fitted to quite a number of 3.8 Es from late 1963 onwards . However, even on the engine change , you might find yourself in all sorts of mismatch problems between flywheel, starter, bellhousing etc - ask me how I know !!

I think there are a few different things in play here. The question of values was raised. Whatever combination of engine/gearboxes are put into the car it will not be matching numbers to the factory so any value uplift would be based simply on the question of whether a 3.8 E-Type is worth more with a 3.8 engine in it or a 4.2? The same question is then present for the gearbox. The latter is a more common deviation from standard spec (although many people keep their original gearbox so the car is still "original"). IMHO I would have thought a 3.8 with a 3.8 engine is worth more than having a 4.2 although any "uplift" would need to be weighed against the cost of doing it.

Turning to the Moss gearbox, I would definitely vouch for its character being different. It takes you back to a different driving style from an earlier era which is why I actually like it in my 3.8 (in a perfect world, I would have my 3.8 OTS and a 4.2 FHC!). There is then the question of whether the differential ratios are adjusted to go with the gearbox (which many people do given the large difference in final drive between the US and European variants).