• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Hobbiest

Thebaddawg

Member
Local time
1:23 PM
Joined
Oct 8, 2017
Messages
15
Reaction score
10
Location
14220
Hello everyone I used to turn wrenches 25 years ago then had to let it fade into a hobby for a more secure and lucrative career. I'm no expert for sure but I may have tried things others haven't and most of you can probably give 90% more advice from your experience than I. I joined to share my research into successfully fitting 489 gears into the 742 case that all started when someone wanting scrap accidentally threw out my only 489 case.
 
Welcome, currently have any mopars? If so pictures are the price of entry into the forum. I’m sure @Cranky can answer your question about fitting gears
 
71 Sebring Plus 510hp 383 ci small block, 06 Charger Daytona #4426 of 5000 and 2007 Ram 2500 650hp 6.7 Cummins
 
Nope.

Sorry.

Gear sets are case specific, although sure grip units are not.

...and welcome, your story sounds like mine.

After 2 years of vocational auto mech, 3rd place in the Plymouth troubleshooting contest, and ASE cert when I was 18, it only took 1 year of full time employment to learn that as a career, it was not for me.
 
1507575027249-1328762758.jpg
489 pinion 742 case
 
People told me I couldn't put 0.060 over 340 pistons in my 360 small block 30 years ago too. They also said I would never get it to run on pump gas or with an 850 spread bore with 12:1 compression and 0.630 lift
 
Last edited:
1507575794705-1363177776.jpg
I'll type this up to be more presentable and include the rest of the necessary info on how to do it later. Sorry for the crappy photo
 
Didn't know that could be done,
I knew a buddy that worked at King bearing
that did some stuff like that he could make stuff work,
that I would have never attempted, missed matched stuff..
BUT;
I guess when there's a will, there's a way...
thinking outside the proverbial box...
But;
why not just get some 742 case gears ? for the 742 case :poke:
I guess if you have all the stuff laying around & get bored,
give it a try :lol:

anyways;
welcome to FBBO, from warm & sunny NorCal Sierra's

good luck & have fun
 
I had a 9 1/4 with 391 gears and a posi. I found an 8 3/4 from an A body that I welded new spring perches on at the pinion angle that worked best for me. I run the 8th mile and wasn't getting out of 1st gear with the 391 after figuring out how to get traction. I came across some Richmond 513 for the 489 for cheap so I bought the 489 and somehow it wound up scrapped. So started my quest to stuff them into the 742 because I read somewhere between year changes Mopar was swapping gears between cases. After much bearing searching I bought the bearings, got the pinion depth set tried to assemble it and found out it wasn't that simple. Anyway with the right shims and bearings it can be done. It wasn't until recently I came across a 489 case for the right price and took it all apart to compare measurements.
 
Hello everyone I used to turn wrenches 25 years ago then had to let it fade into a hobby for a more secure and lucrative career. I'm no expert for sure but I may have tried things others haven't and most of you can probably give 90% more advice from your experience than I. I joined to share my research into successfully fitting 489 gears into the 742 case that all started when someone wanting scrap accidentally threw out my only 489 case.
Had people tell me you could but in all the years I've been messing with them, never tried. Just never had the need to go there.

Nope.

Sorry.

Gear sets are case specific, although sure grip units are not.

...and welcome, your story sounds like mine.

After 2 years of vocational auto mech, 3rd place in the Plymouth troubleshooting contest, and ASE cert when I was 18, it only took 1 year of full time employment to learn that as a career, it was not for me.
When I got my driver's license I started taking care of my sister's 65 Mudstain in turn for letting me drive. Big advantage to me lol especially on the weekend when she was gone out on a date. Anyways, for things I couldn't do, I'd take it to this guy that lived down the street from a friend of mine who did mechanic work on the side. Learned a lot from him plus I hung around the local Dodge dealership shop a lot. One day I took the Mudstain there for a tuneup after the Ford dealership couldn't get it right and the tech let me watch. He even took me under his wing and told me some of his tricks like setting the points a little wide and the plugs a little close so the car would 'drive into the tune' and last longer. Also said that it would help to set the timing at the factory spec or a bit more because it would advance as the points wore down. Stuff like that I used for years. I also looked over all the people in the shop working their butts off and thought that I'd rather do this work as a hobby and not for a living.

People told me I couldn't put 0.060 over 340 pistons in my 360 small block 30 years ago too. They also said I would never get it to run on pump gas or with an 850 spread bore with 12:1 compression and 0.630 lift
You can also do that with 440 low comp pistons in a 400 block. Have to take a little bit off the top if you don't want the compression too high though.
 
Auto Transport Service
Back
Top