You wont be able to use a posi unit from a 2 series rearend with 3 or 4 ratio gears, so make sure you get a 3 series posi if you're buying gears in the 3 or 4 ratios. You can use a ring gear spacer, if you want to save some money, and already have a posi rearend in 2 series ratio.

 

Yeah I will be getting the carrier and using his ring gear and pinion. Prob gonna do Detroit truetrac. Gotta do springs and shocks up front and rear and trac bars first. For now it is great on street and hwy cruise. 1/8 mile is too short to worry about. 1/4 mile is 1-1/2 hours away but I may drive it up there to run it first before so I can compare b4 and after for both. I think it will pick up a bunch in 1/8 but am worried it may run out of rpm on 1/4 with 3.73. I can turn it to 7500 but don't like to usually shift about 6800-7. Right now I shift out of first at over 70 with 25" tire and 2.73's. So I'm really only using first in 1/8 but second shifts and pulls haaard. Pulling 89-92 mph in 1/8 but I see people post faster ets with slower speeds. Why is this. I feel like anyone within .2 in 1/8 would be left in 1/4 since I'm already mile an houring them by 5-10 in 1/8. Any body got anything on this? Thanks guys.

 

Made the trek back tonight and glad. Was perfect weather and I got to make nine passes. Ran my best ever 7.98@ 97. With just a hair of spin. 8.0's consistent. All I need is a better 60' which will be from gear and slicks and cured Happy after getting to run some nicer (tagged, driven) cars that I have never ran. She holds her own for a stock weight, stock suspension, quiet exhaust, 2.73 gears with engine driven fan. I do drive 67 miles one way to get there and drive it almost every day. Got out on an ss, a s/c cts-v, big block gutted something (even body panels gone), couple 5.0's, nice silverado on spray, killed a 350z. May just leave as is for a while until I save up some gas $$... Lol no tagged "all motor" (some not) has got me.


Before exhaust. After exhaust.

 

You wont be over 6,000 rpm's with 3.73 gears when you trip the 1/4 mile lights. You must have a very healthy built engine to be shifting it at 6800 rpm and not having anything come apart!

 

Thank you. Yeah I spent about a year saving and planning and spent the coin where needed. Everything is forged or billet bottom. Main caps are billet which strengthens bottom pretty good. Have had it running about a year now and don't think it doesn't make me cringe every time it goes above 6500. Couldn't see doing BB and be able to drive as work progressed so I have to rev it some to get the power level I wanted. We will see how long she holds, then aftermarket block with big bore and still use most if I don't blow it bad. Will wait till then to use power adders since I have a stock block. A 421-434 sb has a lot of potential. I should be done by never..lol Gears will be done end of June. I will be sure to update. Doing shocks, Trac bars, and 30 spline upgrade. May do springs if poss. Have already done connectors and bushings.