Wanted - chrysler 1600 3.7 diff + 1.75" single carb?

[Whatsanengine?]

Hey guys and girls, I'm ditching the 5-speed idea so I'm after a couple of things to fit my 1975 1300 avenger to make it a little bit faster.. don't know how much I'm going to need to spend? or if you have any other suggestions or good ways to improve my ride let me know, cheers.

[oldschool]

I would advise against putting a 5 speed in a 1300 as they don't have enough power to comfortably maintain 5th in rolling terrain...you'll be needing to change down all the time.

Another factor is the cost and availability. Getting a 5 speed Sierra box is easy, but the Avenger auto bell housing to fit it is very hard to come by...mine cost more than the gearbox!
All up it was about $2500. I have an 80hp twin carb 1600 Alpine and the 5 speed works well...just need to change down on longer hills.

A much easier and cheaper option is to change your 4.11 diff/rear axle for a 3.89 (Chrysler 1300/Hillman 1600) or 3.7 (Chrysler 1600) one. They can be picked up for about $100.
Here's the RPM's using normal 165/80-13 rear tyres.

Hillman 1300 4.11 diff is 85 km/h at 3150 and 5 speed is 105 km/h
Chrysler 1300/Hillman 1600 3.89 diff is 90 km/h at 3150
Chrysler 1600 diff is 95 km/h at 3150

You can drop 100 rpm on those figures at the same speeds by fitting 175/80-13 rear tyres.
I had a Chrysler 1300 (3.89 diff) with 175/80-13 tyres and it felt like it could handle higher gearing.
So I'd go for a Chrysler 1600 3.7 diff, particularly if you're running 165/80-13 tyres.
If your car has 155/80-13 tyres on the rear ditch them...too small!

[Whatsanengine?]

Thanks heaps! okay so scrap the 5 speed swap idea.. and a Chrysler 1600 3.7 diff is the best option? I have 165/80r13s all round at the moment.. also I was given some twin strombergs, would fitting these be useful in any way? cheers

[blekkja]

PRob worth tracking down a 1500/1600 motor from an Alpine before going with twin carbs. In fact TC are painful, if you can track down a big 1.75 from a '76/'77 auto then that would work real good on the 1300 I reckon. I've got one and I kinda regret moving to the twins. The big single gave that much more low down guts and way less hassle for every day driving in town.

[Whatsanengine?]

Okay thanks, ill start looking for those.. any chance you're selling the 1.75 single haha? thanks 

[blekkja]

Nah. I think I may hang onto it. If my twin set up packs up at any stage it would be nice to have to option to go back to it. and they are actually pretty uncommon as I think they only came out on higher spec cars for the short time between dropping TC as an option and then the facelift rationalising trim/options.

[TheMechanicnz]

I think I have one somewhere off a running 1600 Chrysler avenger. Also have the manifold as well, will have a look around tonight for ya.

[Whatsanengine?]

Okay thanks, let me know if you do, I could be keen

[TheMechanicnz]

Hey , just found them and measured the bore and its a 1.5 Sorry about that.

[Whatsanengine?]

Okay no worries, thanks anyway

[brownalpine]

got the 175cd late alpine carb if you can dig up the right manifold cheers