o stock wagon gear question

sg794f · 04-07-2012, 11:33 AM

were building a 71 torino wagon with a 351c (4v) engine for o/sa and need a little advise for rear end gear selection. im thinking a 5.60 ratio. what do you guys think...any advise would be appreciated

Chuck Norton · 04-07-2012, 12:49 PM

What's the total weight of the car/driver on the track? What's your finish line RPM target? What's the low gear ratio in the transmission?

REGGIE WINKLES · 04-07-2012, 12:57 PM

Sounds a bit steep for a hydralic lifter stocker engine, Maybe alright for 1/8 mile. How much will that car need to weigh to make class? Stick or Automatic?

GTX JOHN · 04-07-2012, 05:36 PM

Our O/SA runs 488 gears in good air and 513 at Elevation or Heat.
It runs a pretty high winding 318 Small Block Mopar but 351 may
like Slightly more gear.

O/SA National Recorder Holders

Jeff Lee · 04-07-2012, 06:38 PM

I dont know what gear it needs but keep in mind your better off under gearing a car than over gearing. Start a little conservative and once you get everything ironed out, try different gears.
You'll kill a lot of ET if you over gear but if you're close on the conservative side, you won't be that far off on ET

Tom Goldman · 04-07-2012, 07:15 PM

I know of at least 1 higher class 351 running 5.40 gears, so you may not be too far off with
your guess of 5.60.

sg794f · 04-07-2012, 07:48 PM

thanks for the responses, heres a little more info
the car will weigh 4050 lbs it will have a 351 c (4v) with a hp rating of 300
can for this motor is .420/.450 lift it will have a c4 trans (not sure of tranny gearing yet) looking at a 5000 stall convertor and it will run 1/4 mile
just want to get it out of the hole but not lay over at the top.

thanks kevin

Jeff Lee · 04-08-2012, 01:59 AM

Just to make sure we're on the same page, I see a 1971 Torino SW with a 351C-4V that is factory rated @ 285 HP. Is that the engine you are going to run? Then it is 305 NHRA rated HP, not 300 HP.
Also the specs are a .430"I / .450"E cam, Not .420" / .450".

After looking at what GTXJohn said about gearing (he runs SBM which would have a lot more bottom end than your Clevland), I would start with 5.38's. And you might be right on about the 5.57's.

I believe Pro-Trans will build a TF inside a C4 with better low gearing. Of course that isn't cheap!

For a wagon, I think those are pretty cool. Not Vista Cruiser cool, but I think next best thing.

kwm · 04-08-2012, 07:51 AM

The 4V will not run O/SA The Squire (the heaviest) has a 13.01 weight break with a rating of 305HP it is a natural K/SA.The 2V in the Squire has a weight break of 16.16 and a HP rating of 240 it is a natural P/SA

Bob Bender · 04-08-2012, 08:18 AM

With my 255hp I run 5.86 @ 4400lbs in O/SA.

04-07-2012, 11:33 AM	#1
sg794f Junior Member Join Date: Apr 2012 Posts: 4 Likes: 0 Liked 0 Times in 0 Posts	o stock wagon gear question were building a 71 torino wagon with a 351c (4v) engine for o/sa and need a little advise for rear end gear selection. im thinking a 5.60 ratio. what do you guys think...any advise would be appreciated

04-07-2012, 12:49 PM	#2
Chuck Norton Member Join Date: Dec 2001 Location: Covina, CA Posts: 472 Likes: 92 Liked 76 Times in 17 Posts	Re: o stock wagon gear question What's the total weight of the car/driver on the track? What's your finish line RPM target? What's the low gear ratio in the transmission? __________________ Chuck Norton

04-07-2012, 12:57 PM	#3
REGGIE WINKLES Member Join Date: Jun 2007 Location: St. Augustine, Fla. Posts: 229 Likes: 554 Liked 39 Times in 9 Posts	Re: o stock wagon gear question Sounds a bit steep for a hydralic lifter stocker engine, Maybe alright for 1/8 mile. How much will that car need to weigh to make class? Stick or Automatic? __________________ Reggie Winkles 2650/Stock

04-07-2012, 05:36 PM	#4
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,709 Likes: 2,737 Liked 2,400 Times in 680 Posts	Re: o stock wagon gear question Our O/SA runs 488 gears in good air and 513 at Elevation or Heat. It runs a pretty high winding 318 Small Block Mopar but 351 may like Slightly more gear. O/SA National Recorder Holders

04-07-2012, 06:38 PM	#5
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: o stock wagon gear question I dont know what gear it needs but keep in mind your better off under gearing a car than over gearing. Start a little conservative and once you get everything ironed out, try different gears. You'll kill a lot of ET if you over gear but if you're close on the conservative side, you won't be that far off on ET __________________ Jeff Lee 7494 D/S '70 AMX

04-07-2012, 07:15 PM	#6
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,468 Likes: 874 Liked 838 Times in 232 Posts	Re: o stock wagon gear question I know of at least 1 higher class 351 running 5.40 gears, so you may not be too far off with your guess of 5.60. __________________ Tom Goldman 1500 SG , 1506 STK

04-07-2012, 07:48 PM	#7
sg794f Junior Member Join Date: Apr 2012 Posts: 4 Likes: 0 Liked 0 Times in 0 Posts	Re: o stock wagon gear question thanks for the responses, heres a little more info the car will weigh 4050 lbs it will have a 351 c (4v) with a hp rating of 300 can for this motor is .420/.450 lift it will have a c4 trans (not sure of tranny gearing yet) looking at a 5000 stall convertor and it will run 1/4 mile just want to get it out of the hole but not lay over at the top. thanks kevin

04-08-2012, 01:59 AM	#8
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: o stock wagon gear question Just to make sure we're on the same page, I see a 1971 Torino SW with a 351C-4V that is factory rated @ 285 HP. Is that the engine you are going to run? Then it is 305 NHRA rated HP, not 300 HP. Also the specs are a .430"I / .450"E cam, Not .420" / .450". After looking at what GTXJohn said about gearing (he runs SBM which would have a lot more bottom end than your Clevland), I would start with 5.38's. And you might be right on about the 5.57's. I believe Pro-Trans will build a TF inside a C4 with better low gearing. Of course that isn't cheap! For a wagon, I think those are pretty cool. Not Vista Cruiser cool, but I think next best thing. __________________ Jeff Lee 7494 D/S '70 AMX

04-08-2012, 07:51 AM	#9
kwm Junior Member Join Date: Dec 2005 Location: London KY Posts: 95 Likes: 752 Liked 4 Times in 3 Posts	Re: o stock wagon gear question The 4V will not run O/SA The Squire (the heaviest) has a 13.01 weight break with a rating of 305HP it is a natural K/SA.The 2V in the Squire has a weight break of 16.16 and a HP rating of 240 it is a natural P/SA __________________ Kenny Miracle P/SA 310

04-08-2012, 08:18 AM	#10
Bob Bender VIP Member Join Date: Jan 2009 Location: Maryland Posts: 1,727 Likes: 1,589 Liked 452 Times in 88 Posts	Re: o stock wagon gear question With my 255hp I run 5.86 @ 4400lbs in O/SA. __________________ Bob Bender 144 O/SA 2010-2012 National Record Holder