comparing 2 MC's

[Livolsi, Stephane]

I have a question for the tuning gurus amongst us.

For the past 5 years I have been driving an 86 5kcstq, totally stock and
just turned over 300,000 kms.  I did a lot of maintenance work, but no
horsepower upgrades - the car is totally stock (ok, except for the high hp
yellow pokemon stickers)

Last month I bought a totally stock 88 5kcstq avant which has about
250,000kms.
As I understand it, these 2 cars are pretty much identical in the engine bay
- engine size, intake, ignition, etc.

What I have noticed is that the 88 seems to have a bit less low end grunt
and a whole lot more top end.  After about 3200 rpm it just rockets up to
6000 very easily and smoothly.

On the other hand, the 86 seems to have a bit more pull at the lower end,
and seems to peak out at a lower rpm - about 5000ish.

As far as I know, neither car has had any modifications from stock that
would affect the acceleration, etc.

Does anyone know of any differences that might account for this?  Could the
timing belt be moved over a tooth on one of them? would that account for it?
Different turbos?
Now that I think about it a bit, the exhaust on the sedan is not quite
stock, it is stock diameter pipe, but the rear muffler is very free flowing.
However, I would think that this would improve top end breathing and this is
on the car that doesn't like the top end.

This isn't a problem or concern, I just thought I'd throw it out there and
get some opinions

Thanks

Stephane