Bud:
It is important to make sure that all of the pieces work
together. You will need to check the distributer number to make sure
that it has the correct characteristics for the carbs. You can use
either of the two distributers once you know what vac/cent.
characteristics they have. With the HS4 carbs you can either plumb the
vac. adv. to the ported fitting on the rear carb. Or you can pick up
vacuum at the manifold. Either system works with the correct dist. The
most documented layout would be the HS4 and an early (non-HIF) 25D.
Once rebuilt with high comp. pistons and an early cam you would have
specs similar to 62-67 cars. The factory designed this setup for the
best balance of power for normal usage.
Get me the dist. numbers and I will check to make sure they are
suitable. Also check the dist. shafts for wear and vac. units for
operation. To my mind the best bet for you would be a new 45D dist.
suitable for the HS4 carbs. Pricey, but set and forget. There is a
Pertronix conversion for this dist.
Kelvin.
-----Original Message-----
From: Bud Krueger [mailto:bkrueger@ici.net]
Sent: Wednesday, November 25, 1998 9:32 PM
To: MG List
Subject: 25D4 vs 45D4
A bit of advice, please. My '77MGB has HS4's and an early twin downpipe
exhaust
system (once I get around to installing it). I will be using a
Pertronix
ignition system. My problem is this: I have a 25D4 and a 45D4
available to
me. Which one should I use? Why? TIA.
Bud Krueger
52TD
77MGB
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