torque convertors and crawl ratio

[scotty]

does anuone have any idea how to figure torque convertor slippage into a final drive ratio?

im about to swap a t18 and dana 20 into my grand wag,but im alittle sad http://www.cs.colostate.edu/~zeimet/ubb/frown.gif about losing of the low range from the dana 300(2.61 vs 2 of a dana 20)

not figuring torque convertor slippage,the granny gear of the t18 should make up for it. my current "crawl"(first gearxlow rangexaxle gear) is 2.94x2.61x3.31=25.4 . with the t18 it will be 6.39x2x3.31=39.24,which sounds a whole lot better,even with a higher low range.

does anyone have any idea how to igure in torque convertor slippage into this equation?



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scott
85 grand wagoneer
258 with motorcraft 2bbl/904/twin stick dana 300/dana 44/welded amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd

T18/dana 20 swap very soon
searching for dana 18 to replace the 20...

[Paul]

I have a question for you: what is used to adapt your Dana 300 to your auto. trans? I have a TF727 and an NP228;I'd love to swap to a Dana 300 but I wasn't aware that any adapter was available to attach it to a 727. (This, of course, assumes the output ends of your auto and mine are the same). Any thoughts would be appreciated. Thanks!
Paul

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'86 GW "Warhorse"
360 Edelbrock Perf. Pkg.
Dana 60 rear, Trac-loc, 3.73's 32x11.5 BFG AT ko's

[scotty]

no adapter needed.the dana 300 will bolt right to the factory NP circular adapter and 23 spline output of your 727.however,you will need at least 4 inches of suspension lift for adequate front driveshaft clearance,even using the skiniest possible front shaft. i installed a 727 and found out the hard way that the front shaft rubs the pan on the 727 at stock height.this is why im currently using a 904,even tho it is kinda tired. the 904 is much skinnier and i now have room for a 2 inch front driveshaft. http://www.cs.colostate.edu/~zeimet/ubb/smile.gif the 904 and 727 share the same tranny to xfer adapter,and both have the same 23 spline output. if youre willing to lift it for driveshaft clearance,all you need to do is swap in an early front axle,and reroute exhaust. the dana 300 now occupies the same space as the catalytic convertor. there are a couple of pics of it on bob barry's wold wagoneers site.

my thoughts?its well worth doing. the dana 300 is an awsome gear driven xfer case,and driving around in front wheel drive,or rear wheel drive low range off road is lotsa fun with a twin stick shifter. one of the silliest,funnest things i did last weekend was some cool backwards doughnuts in FWD low in a big,open muddy field at haspin acres. http://www.cs.colostate.edu/~zeimet/ubb/biggrin.gif



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scott
85 grand wagoneer
258 with motorcraft 2bbl/904/twin stick dana 300/dana 44/welded amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd

T18/dana 20 swap very soon
searching for dana 18 to replace the 20...