Top Loader gear ratios

[J Tibett]

I have a SPO Cobra with a 427 fe with a top loader. I am wondering what the gear ratios are in the top loader. I am considering changeing to a tremec 5 speed. Cruising at 70mph I am currently at 3,500rpm. What do I give up with the tremec and what do I gain

[renaissance man]

Here are the gear ratios. Go to www.4speedtoploaders.com

Gear Ratios

Close

first second third fourth
Ratio 2.32 1.69 1.29 1.0
Tooth Count 32 28 25 23
Counter Gear Tooth Count 15 18 21 25

Wide

first second third fourth
Ratio 2.78 1.93 1.36 1.0
Tooth Count 32 31 25 23
Counter Gear Tooth Count 15 21 24 30

Pros and cons depend solely on what you want. I have a 289 with a Toploader, and 410 rear end, and run 3700 at 70mph. I love that Nascar sound! With a 5 speed you'll get about 600 or so rpm savings and a bit quieter ride but lose power and time needing to downshift. The 4-speed has a 1:1 ratio in 4th gear so what your engine puts out is going straight through to the rear end.

What rear end do you have in the car?

[J Tibett]

Thanks for the info. The rear is a 373.