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MG MGA - 1800 + Sierra + 3.9 Rear End

Is anyone running this combination? Comments on fifth gear performance with the 3.9's
Thanks,
Doug
D Sjostrom

Doug - Really looking for tickets aren't we? ;) Dave
David DuBois

My wife's a cop ;)
D Sjostrom

Doug

I'm running 1893cc with power mods, 1 3/4 " SU's, 5 speed box and 3.9 diff. 3000 rpm in 5th =69 mph. Pulls up to 100 easily and beyond if you've got the nerve, actually done 115 mph ( don't tell anyone ) I must be getting old because I start to think what would happen if you crashed in an 'A' coupe, lots of sharp solid things, no air bags etc. Anyway back to the plot, this combination lets use cruise at 70-80 effortlessly

Getting old Terry
Terry Drinkwater

I am running that combo. The fifth gear allows Interstate highway cruising at 70 mph @ 3200 rpm (but my speedometer reads a bit on the high side of actual...GPS measured). Terry's 69 at 3000 is probably spot on. The 3.9 is a bit slower on take off in first gear than was my 4.1...can't get the rubber I used to get. That said, it is not a dog either. It runs like what it is, an MGB in an MGA's clothing. All gear ratios (1-4) are exactly the same as the MGA's tranny. But that fifth gear is sweet. I did these mods specifically to make it a great car for road trips, and it is. I also added front disc brakes, pertronix ignition, alternator, anti-sway bar, etc. All worth doing in my book.
Frank Nocera

Thanks Guys,
Frank, that is exactly what I've done also. Discs, swaybar the works. I have the 3.9's in waiting in case I don't like the 4.1 rear. I'm at least six months away from re-joining the body to the (driving) chassis, which goes like stink!
Regards,
Doug
D Sjostrom

I am blessed to have that combination. The biggest motivator was to get that beautiful fast-looking car our of the slow lane! Also to be able to drive as fist as I care to w/o hurting it. With some mods to the 1800 (flowed head, 9:1 compression, Piper 270 kit, Aldon dist., re-jetted carbs...) I suspect top speed, with thoses tall gears, may be in 4th. I have not shot for top speed yet, hope to, but like Terry, getting old I guess. Gets scary and I dont need a triple-digit ticket. It is a much better, capable and more relaxing road car though. First gear acceleration is sufficent to spin 165s as much as you care to.
Steve
Steve Meline

If anyone needs a 3.9 diff, I have several.
James Woolf

I also have that combo. It is a sweet set-up to allow for freeway crusing. The second gear is NOT the same as the MGA. You can wind it up a little longer than a stock. The other guy will wonder how you are beating the pants off of them.!!!!!
JEFF BECKER


A friend in Jacksonville has an 1800 coupe with "1800" in stainless on the body btween the chrome air outlets abd the front wings, a'la the Twin Cam lettering on those MGAs. Wish Moss or someone had those stainless "1800" designations available!
Frank Nocera

The only thing that you could do to beat this combination is to install a supercharger. Moss about $2500. sweeeet!
JP Jim

Can anyone point me at sources for a 3.9 diff this side of the water?

Shane
shanerj

Shane,
Try these folks.

http://www.autogear.co.uk/product/catalogue.php?manufacturer=&groupid=5&start=100&model=

BOL,
Doug
D Sjostrom

Doug,

Thank you; I have never been able to get past page one on their website; you have broken their code for me.

Shane
shanerj

This thread was discussed between 12/10/2005 and 20/10/2005

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