curt76280 Posted October 11, 2009 Share Posted October 11, 2009 I recently purchased a 3.90 r200 for my 76 build,an 83 l28 engine and tranny.Iam planning on using the 83 block and head .040 over,head work on the p79, 272 cam,msa header and bob sharp 4 barrel intake and 390 holley ,dont scream about su's.I will eventually source a set and do a dyno comparison and run the best setup My question is this, has anyone ever used a 5 speed from a 720 pickup? I can get 1 for $50.00 and the ratio is as follows 1st 3.592 ,2nd 2.445, 3rd 1.415, and 5th .813 Quote Link to comment Share on other sites More sharing options...
curt76280 Posted October 14, 2009 Author Share Posted October 14, 2009 yes,no,maybe? Quote Link to comment Share on other sites More sharing options...
blackwidow Posted October 15, 2009 Share Posted October 15, 2009 I don't know how you plan to use your car, but I would want a lower 5th for the rear you just got. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted October 15, 2009 Share Posted October 15, 2009 If its for racing then i would go with it. If its for a cruiser, or driver i would go with something different. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted October 15, 2009 Share Posted October 15, 2009 I don't know how you plan to use your car, but I would want a lower 5th for the rear you just got. Contrar! I like what you've got there! Multiply the final drive by your 5th gear ratio and it comes to 3.18. In a small car like the Z, you'd have good response and economy. The other ratios are good too! It'll be quick off the line IMO. My stock Datsun 280C ran an auto with 4.11's final drive. Then I put in a 5 speed with a 0.86 o/d and that was a revelation. It worked out to 3.53. The next 'box I put in had a 0.75 o/d and that lost me quite a bit of acceleration in 5th but my car weighs in @ 3200 lbs! (Overall 3.08 ratio) You won't have any problem with your car. I say get it. The price is right as well! Cheers. Quote Link to comment Share on other sites More sharing options...
curt76280 Posted October 15, 2009 Author Share Posted October 15, 2009 Thanks OZconnection I think this will be a good setup for its intended purpose, which is not going to be a daily driver. I am building this to be a toy and something to possibly try out all the ricers I have to deal with on a daily basis on the way to work,sorry if that offends . And I also have a 83 model 280zx tranny as well that I can swap if it is too tall of a ratio ,which i suspect it wont be ,I have allways been more partial to 1/8 mile runs but that is just my preference. As it stands,p54 block .flat tops,p79 shaved 80 thousandths,shimmed ,n42 valves, sent my stock cam to delta for a regrind along with the followers,bob sharp 4 barrel intake,holley 390 cfm reworked,msa header,and still buying parts.Possibly triples or a stand alone ems in the future as cash flow dictates and then on to the full restoration of the car,and yes i know most people restore the car first but I cant resist the urge to do the engine first ,I have done this on every build I have ever done. I would like to thank everyone for any input on my posts positive or negative,I appreciate all information. Quote Link to comment Share on other sites More sharing options...
Xnke Posted October 15, 2009 Share Posted October 15, 2009 Curt, what regrind are you getting? make sure you upgrade your springs if you are going over .450" of lift. (the .480"/280* grind cam is really only .450" lift, but the duration is correct and others have said it's a good street cam.) I have that regrind, but don't have the engine running yet. My head is still in the shop and then it'll be a bit before i have a running car still, as most of the bodywork is still yet to be done. I also have a similar 5 speed, but my OD is .830, and I have a 3.36 ratio R180. We'll see if i need to get a 3.7 or 3.9 ratio diff later on, as my 3.36 is in perfect condition with only 33K miles on it. Quote Link to comment Share on other sites More sharing options...
curt76280 Posted October 15, 2009 Author Share Posted October 15, 2009 That is the exact cam I am using. thanks for the info though,I too have read that is a good choice for street use.Good luck on your build and shoot me some pics when you get it done.Thanks, Curt 274 grind= 274 duration 234 @.050 .464 lift and 107 centerline Quote Link to comment Share on other sites More sharing options...
MAG58 Posted October 17, 2009 Share Posted October 17, 2009 I don't think there is a problem with the 720 trans, you'd have to put a different bellhousing on it if it came out of a Z motor, since it leans the wrong way (it's still the 71B iirc, so taking a Z car front off of a trans and putting it on yours shouldn't be difficult) The one thing I'm not sure you'll like is the 1st gear. All the truck transmissions I've seen (including the one on my dad's 720) have super low 1st gears. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted October 17, 2009 Share Posted October 17, 2009 The one thing I'm not sure you'll like is the 1st gear. All the truck transmissions I've seen (including the one on my dad's 720) have super low 1st gears. It's not that bad......I ran a 4.86 ratio in the diff with my 5 speed at one time. You certainly don't have to slip the clutch at all with this sort of gearing...it will save your clutch in the long run. As far as 'off the line' response is concerned, I hope you can change gears quickly . I know my car is a street driven vehicle, but geez I had some fun with some much quicker cars! They'd pass me later on after I gave it a bit, them shaking their head going WTF! . Its addictive man. Cheers!! Quote Link to comment Share on other sites More sharing options...
curt76280 Posted October 18, 2009 Author Share Posted October 18, 2009 That is exactly what I am looking for a very quick holeshot and decent topend I feel that with this tranny I can obtain a happy medium, with the happy part being takeoff and the medium being topend useage!Thanks everyone for your input. I have sent a P.M. to Braaap to see if it is allright to post in the classified I have some parts I think some of you may want at a great deal,I have been a member long enough but don't have my 40 posts yet ,So hopefully I will be allowed ,and if not I will post what I have left after I receive my 40 post mark,and thanks once again. Quote Link to comment Share on other sites More sharing options...
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