Ls swap with np205 or np241

[wannabefastcrf]

I am trying to compare these two options. The trans is a 4l65e. If I use the 205 I will need a $650 adaptor but the stock speedo will work. I think a switch for low range is not needed but maybe someone can tell me. I also have a np241 with vvs so no adaptor is needed but a modified crossmember is needed and a electric speedo , driveshafts. and a switch for low range tuning. Sound right? Seems like the 205 is the better choice.

[franken]

Probably comes down to weight, ratios, and strength. Your choice.

The 241 is lighter.
The 241 has a 2.6:1 low vs the 205 ~2:1
The 205 is a lot stronger and gear driven.

The 241 input is a 6 bolt round pattern. Do you have a similar input 205? They aren't that common.
In either case, the inputs need to be 32 spline for that trans if I recall. What's the spline count on the 205 and 241?

[wannabefastcrf]

The 205 and 241 are both 27 spline (205 is stock in my k5 now). Either is ok strength wise as it's not a real heavy vehicle and tire size is 33s. I'm really more interested in figureing out which will be the cheapest / easiest to make work in a ls swap. I want to retain the stock gauges and looks in the interior.

[Cobalt964ruf]

205 would be my choice

[wannabefastcrf]

Hey it looks like you have a lot of experience in this area! With your 4l80e set ups is your speedo off the transfer case and vvs off the trans? How does it act in low range. I like the idea of using the 205 as well BC it seems like it will be easier and retain more factory parts. Only down side is the cost of the adaptor which doesn't seem much cheaper when I compare everything else to make it work

[Cobalt964ruf]

in a perfect scenario, you need a 2wd application 4l80e and the vss and iss run solely off of the trans and the 205 is just an afterthought and has no electronic needs or run issues. all 4l80e's are 32 tooth outputs and even the 2wd trans will bolt up in a 4wd drive application. the key here is the 2wd trans comes with the iss and vss rings inside the trans. if using a 4wd application 4l80e, you will need to make a vss 40 tooth ring and and mount for the oem vss switch and mount it on the driveshaft yoke output area to register. not hard to do, but if a hardcore wheeler then you likely need to build a rock guard around the vss setup. have fun and happy motoring

[Cobalt964ruf]

there was a one year only 205 from the 1991 1ton ccsrw trucks that had a vss in it. but they are extremely rare and hard to find. and some guys will remachine the speedo output threads to use a vss in that location. but also have to install a 40 tooth ring from like a 241c. again, 2wd 4l80e mated to a 205 is your best option.