'81 El Camino Build

[djdiede20]

Hello everybody I am new to the forums. I have a 81 El Camino that I just recently bought a 383 stroker to put in paired with a Ford 9" with 3:73 gears. Need some advice as the transmission that is currently in it is just about to say goodbye especially once we get it on the road. I want to have decent top end where its not rapped out running 60. I haven't got it on the road yet, but would like ideas. Also I'm 22 and pretty new to the game but ready to learn and I really wanna get this puppy out on the road.

Thanks!

 

[BlairC_789]

Great to see another young guy around here
Transmission wise I would definitely try to get a 200r4 or a 700r4 so you can get an overdrive.
Currently I have a metric200 (3 speed) and ill be swapping over to a 700r4+an 8.8 soon as I find a used set of 3.31 gears.
If you need some advice on selecting transmission, changing crossmember, drive shaft shortening, etc. just shoot me a question. I'm sure others would be willing to help out with anything as well.

 

[djdiede20]

I would really like to keep it a manual I should've added that. Would you have any recommendations for a manual set-up? Looking at the TREMEC TKX 5spd if anybody has a set-up with this and what gear ratio you run. Thanks for the reply who knows maybe Ill come to my senses 😊

 

[BlairC_789]

I would really like to keep it a manual I should've added that. Would you have any recommendations for a manual set-up? Looking at the TREMEC TKX 5spd if anybody has a set-up with this and what gear ratio you run. Thanks for the reply who knows maybe Ill come to my senses 😊

are you looking for a daily driver, street/strip or just a race car?
I know those Tremec T5s have different final drives depending on what you get, I think the ratios are around .7-.8 Which is similar to the 200r4 &700r4 of .67 and .7
typically with 26.1" tires and the .67-.7 final drive I've seen people running 3.08s up to like 373 or even 4.10s.
Also take into considerations the ratio of your first gear. If a transmission has a first gear ratio of 3.27 and you have a rear end ratio of 4.10 that's equivalent of someone with a Th350 with 5.32 gears! (basically useless for a daily driver)
https://spicerparts.com/calculators/transmission-ratio-rpm-calculator I use this tool when looking at finding the optimal gear ratios. It doesn't take in parasitic loss and wind resistance but it gives you a good starting point.

 

[djdiede20]

I would say more of a daily. But its not a car that I actually plan on driving daily if that makes any sense. More of a fun burn some rubber and run through the gears every couple weeks type of car. Could you elaborate more on the gear ratio from transmission to rear end. What's more applicable for a daily driver vs just a good set-up for a badass el camino?

 

[Ugly1]

I would really like to keep it a manual I should've added that. Would you have any recommendations for a manual set-up? Looking at the TREMEC TKX 5spd if anybody has a set-up with this and what gear ratio you run. Thanks for the reply who knows maybe Ill come to my senses 😊

Ah now you’re talking a different game! If you’re of FB there are a couple of manual g body sites. Depending on costs I have only heard good things about those transmissions. I personally have gone the less expensive route. NWC Camaro 5 spd. You can find the Temec transmissions used but few and far between. You can look up what the Camaro’s ran with on the RS and Iroc’s to get an idea of gears.there is also a site( not sure if I still have it) that you can put in your gears on the transmission and rear end along with the cam rpm and it calculates out the top end speeds this is one of them spicerparts.com

 

[BlairC_789]

I would say more of a daily. But its not a car that I actually plan on driving daily if that makes any sense. More of a fun burn some rubber and run through the gears every couple weeks type of car. Could you elaborate more on the gear ratio from transmission to rear end. What's more applicable for a daily driver vs just a good set-up for a badass el camino?

Here's a chart of the TKX transmissions that are offered (there might be more but this is all that was on the chart)
Transmission ratios work the same as the rear end ratios. Bigger ratio number=shorter gear/lower speed. Smaller ratio number=taller gear/higher speed.
Tire size can also have a big effect on rpms. A taller tire will reduce your cruising rpms but will reduce your power. For example a 29" tire will give better cruising rpms than a 26" tire. When you see someone put larger mud tires on their truck thats why they will typically swap in a set of lower differential gears at the same time. You can find your tire height here

Looking at the chart there's 2 different 1st gear ratios (3.27 and 2.87). If you pick one with 3.27 instead of the 2.87 you'll have more power off the line meaning you'll be able to burn some rubber
There's also a couple different options for the 5th gear ratio. (.68, .72, .81). The smaller the ratio means lower cruising rpms. . 68 in theory would be better for cruising than the .81 ratio.
I say in theory because it depends on your rear end gearing.
a transmission with a .72 gear ratio + rear end ratio of 3.73 will have the same cruising rpms as if you paired a transmission with a .81 gear ratio + rear end ratio of 3.50
All I can say is mess around with that Spicer Parts calculator when you get to looking for a transmission.
With you wanting to cruise around 60 my safe recommendation for gears would be anywhere between a 3.50 up to a 4.10 for your rear end ratio. Maybe even up in the 4.30 range.
Your 3.73 will probably work well.

 

[mclellan83]

glad to hear you are keeping the manual

 

[djdiede20]

Man you guys are awesome! Took awhile for me to understand the concept but now I'm on the same page. Thanks for all the info!