Inliners International Forums General Discussion Drive Train Gear Change

OK now that I have the cam choice done (comp 260) I think I may be in need of gear change. Right now the rear gear a 2.41 7.5" axle from a 78 El Camino. The trans is a Saginaw 4 speed with the following ratios 3.5, 2,47, 1.65 and 1:1. With a 4500-5000 projected shift points I will have 39-44mph in first, 55-61 second and 83-92 in third. The 60 mph cruise rpm is about 1950.

I do not want to loose any street drivability but also want to be able to get out of the hole quickly ( I do some 1/8 mile drags) I was thinking on 3.23 or 3.42. Right now my tire size is 205/60 15. I can change to a taller tire if needed too, maybe a 205/70 or 205/75. Oh yeah the car is a 1962 Chevy II

If you went with a 3.42 gear it would be almost like driving down the road in 3rd gear now. 2.41x1.65=3.9765. If you wanted to kinda see what it would be like put on some 235/75/15 and head to the nearest freeway in third gear. If I had your combination I think 3.08 would be the best combo for not loosing driveability but going quicker in the 1/8 mile.What speeds is the car going at the end of the track? 5000 Rpm in third gear would be about 73mph 4500 would be about 66mph in third with a 3.08 axle and 24.9 inch tall tire. With a 60 mph cruise rpm being~2500rpm. A lot would depend on what gears you can get cheap and easy. After all some fine tuning can be done with tire height. I am sure other people will post up with their ideas. Jay 6155

My only time at the track I had really bad traction, and spun the fist 70 feet or so, I am shooting for 70 at the traps. I have no freeways around me, and only have about 15 minutes on one on the way to the track.

Keep in mind that Saginaw's aren't real strong trannys, they were put in a lot of Vega's, Monza's and low HP 4 cylinder vehicles. And in a heavy car like this may be troublesome.

I abused one in my '53 pickup behind a pretty stout 270 for years with no problem. Put in a T 5 and gave the Saginaw to a young friend for his small block powered Model A. He blew it up almost immediately.

If it does go I'll replace it with this.
http://www.jegs.com/i/Richmond-Gear/836/1304000071/10002/-1?parentProductId=

I all ready have a Hurst competition shifter.

If 70mph is the goal,then 3.08 will get you there. If you make more HP than you think with the "260" cam then put on a little taller tire. That will decrease rpms at the end of the track. So will the T-10 with its different 3rd gear. At this point 4th gear becomes a poor mans overdrive to get you to the track. My understanding with the sag 4spd is it is real weak in reverse. I don't have any experence with this trans. Jay 6155

Poor mans overdrive is exactly why I went with the trans. I can use all three gears instead of two with a th350, and still drive at highway speeds! I do not know much about them, all I know is mine works great and only cost me $200 with proper ChevyII bellhousing! I wonder if a T5 is stronger???

Sadly, I can't help there either. All I know about T5s is that there are different ones out there with different ratios. There is also something called "world class", I don't know (but would like to learn) what that means. I used to own an 89 Chevy 1/2 ton pickup with a 5 speed that was nice I just don't know who made the trans. Jay 6155

There is a good chart in our "Tech Tips" section that shows T5 ratios and applications. There are also several ratios to choose from in the Saginaw. Also Patricks sells a modified Hurst shifter that moves the stick forward into a much better place. His catalog shows the Saginaw ratios but the online catalog page is hard to read. PATRICK'S

Pretty mild 5.0 Mustangs can break a T5 without a lot of effort and they only weigh 3000-3200 lbs., an El Camino is a lot heavier and probably can break them just as easily if driven hard. A good adjustable PP can go a long way toward softening the shock of dumping the clutch though.

The axle is out of a El Camino, the car is a 62 Nova that weighs about 3000 with me in it and a full tank of gas.

Ok gotcha, I mistook your car as the El Camino and not the rear end.

It was one of those free and was the correct width deals. Little more work but worth it.