Dana 300 Replace np231

[themauler]

Hello ,

I need some guidance as this has been on my mind for the past week. Basic story and I'll try to keep it short.

I like to tinker and do challenging upgrades that can fit my modest budget. I have wheeled on stock axles (regeared, trussed, for 35s) for sometime now and am getting the itch for tons. I am also prepared to go all out on the np231 with the HD chain, planetary, and full SYE.

Just recently I have an opportunity to pick up a late model dana 300 for one hundy. (This gets me pretty excited :yelclap Now I am left with two choices. Run it normal side up = passenger drop or run it flipped = driver's drop (this is behind a 4.0/ax15). My options for front axles is chevy 60 or ford 60. I like the choice because of my budget and what good deals pop up on craiglist or what not.

This is where I need people's experience and advice.
1.) Say a good deal on a chevy 60 pops up. Is setting up a 3 link on the passenger side a total PITA? Is the driveshaft going want to make contact with the starter with only mild lift (4"-5")?

2.) Will the stock outputs of the dana 300 live to east coast wheeling and 37s (prob 5.38 gears)? In the future instead of doubling it behind a np231 I plan on buying the lowmax 4:1 gears.

A picture of a driver's side drop set up would be really helpful for me to visualize. And if this all seems too unrealistic I can ditch any plans for a chevy 60 and run the 300 flipped.

TIA

 

[ftwelder]

I can't answer your questions but when faced with the same questions I went with a flipped 231 rangebox doubler hooked to a D300 flipped and a '89 F350 driver drop axle . also running 5:38 with 37" AX15. The parts fit nicely. 3 link with upper on passenger side.

 

[themauler]

I can't answer your questions but when faced with the same questions I went with a flipped 231 rangebox doubler hooked to a D300 flipped and a '89 F350 driver drop axle . also running 5:38 with 37" AX15. The parts fit nicely. 3 link with upper on passenger side.

Have you had any concerns with the strength of the 300 in your situation?



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[srb531]

w/ all that much reduction imo the weak link will be the transmission. last jeep i had was a cj w/ d 300 , 32 spline hd outputs, 4.1 kit , 4.56 gears & 37's. tranny was a th 350 w/ only a 2.73 1st gear . but in 1st gear low range it was serious low speed crawl.

 

[VAhasnoWAVES]

the weak link of the dana 300 is the rear output. itll typically be the first thing to pop with a stock case. upgraded front and rear outputs as well as 4:1 gears are readily available, and it most rear output upgrades can be bought with provisions for a factory style VSS. if using it drivers drop, you will need to flip it with a clocking ring, and make sure you get good engagement with the transmission (a long enough input gear on the 300).

the bigger issue i see is that it will significantly lengthen your rear driveshaft, and shorten the front, without being behind some sort of crawl box. will it bay be advantageous in something like a TJ to lengthen the rear driveshaft, our front shafts are rather short in comparison.... youll loose a significant amount of droop due to drive shaft bind. (this is assuming stock wheelbase)

 

[themauler]

w/ all that much reduction imo the weak link will be the transmission. last jeep i had was a cj w/ d 300 , 32 spline hd outputs, 4.1 kit , 4.56 gears & 37's. tranny was a th 350 w/ only a 2.73 1st gear . but in 1st gear low range it was serious low speed crawl.

47.5:1 is my current "crawl ratio" 82:1 would be my ratio for my desired setup. I have never heard of any issues with these trans behind a 4.0 HO besides syncros :dunno:

the bigger issue i see is that it will significantly lengthen your rear driveshaft, and shorten the front, without being behind some sort of crawl box. will it bay be advantageous in something like a TJ to lengthen the rear driveshaft, our front shafts are rather short in comparison.... youll loose a significant amount of droop due to drive shaft bind. (this is assuming stock wheelbase)

Because of the driveline length do you see it better to build the 231/300 combo instead of the 4:1 lomax gears?

I believe I picked up an 84 dana 300. Can the VSS fit inside the tail housing?

 

[VAhasnoWAVES]

Because of the driveline length do you see it better to build the 231/300 combo instead of the 4:1 lomax gears?

I believe I picked up an 84 dana 300. Can the VSS fit inside the tail housing?

on my personal build... my driveshaft operating angle is the limiting factor in my front suspension. i wouldnt want to make it any shorter. if you look at the shape of the 231 and 300... the front output of the 231 sits flush(ish) with the mating surface to the trans, where the front output of the 300 sits proud. you would be shortening that shaft. adding a crawl box helps to eliminate this, but adds complexity.


as for info on what you have and what you can do with it, novak adapters has good info on this Tcase.