Anybody running a 4L80E trans behind their bigblock? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

HeavyHauler · 04-15-2020, 03:12 PM

I am looking at getting a 4L80E to put behind my 1975 454 engine. Has anybody else done this. If so then what parts did you use and what modifications are needed to make it fit a 1968 Chevy C10 shortbed.

2500HD · 04-15-2020, 05:00 PM

I am behind a ZZ454. You will need a controller. I am using a Compushift 1 now but i am currently changing over to a Compushift sport. Will need a new trans cross member or the factory one could be used but you will have to slide it back some. Will need a TPS . Lastly, you will need to shorten the drive shaft. I have a factory high hump cab so i do not know if there will be any problem with a low hump.

HeavyHauler · 04-16-2020, 03:08 PM

Quote:

Originally Posted by 2500HD

I am behind a ZZ454. You will need a controller. I am using a Compushift 1 now but i am currently changing over to a Compushift sport. Will need a new trans cross member or the factory one could be used but you will have to slide it back some. Will need a TPS . Lastly, you will need to shorten the drive shaft. I have a factory high hump cab so i do not know if there will be any problem with a low hump.

Do they sell a aftermarket crossmember to fit this trans so I dont have to drill any extra holes or hack up my original frame?

What did you use? My truck is a original factory 396 bigblock with 400 turbo trans.

2500HD · 04-17-2020, 03:12 PM

Factory big block trucks came with the high hump so you are good there. I used a CPP cross member. If i recall i had to drill 2 holes per side in the lower frame rail. If you use the factory cross member you will have to drill hose in the upper and lower frame rails. Really isnt a big deal the holes are 7/16 i think. I assume you have a two piece shaft. What bearing do you have? this is a good time to change to a single shaft. Are you lowered or factory height?

ImNoSpaz · 04-17-2020, 05:23 PM

I have the low hump and had to fold over the seam at the bottom of cab/tunnel to give the trans a little bit more room. I also tried the aftermarket trans cross member but was not willing to drill holes, so I made my own.

I have the 7.4 vortec with the 4L80e, and used the Ron Francis wiring kit. That's all that was available at the time of purchase. Driveshaft, if I remember right was a 3" aluminum out of a little 80 something c10 and was the perfect length.

04-15-2020, 03:12 PM	#1
HeavyHauler Registered User Join Date: Nov 2011 Location: USA Posts: 414	Anybody running a 4L80E trans behind their bigblock? I am looking at getting a 4L80E to put behind my 1975 454 engine. Has anybody else done this. If so then what parts did you use and what modifications are needed to make it fit a 1968 Chevy C10 shortbed.

04-15-2020, 05:00 PM	#2
2500HD Registered User Join Date: Aug 2005 Location: DFW Posts: 268	Re: Anybody running a 4L80E trans behind their bigblock? I am behind a ZZ454. You will need a controller. I am using a Compushift 1 now but i am currently changing over to a Compushift sport. Will need a new trans cross member or the factory one could be used but you will have to slide it back some. Will need a TPS . Lastly, you will need to shorten the drive shaft. I have a factory high hump cab so i do not know if there will be any problem with a low hump. __________________ 1970 Custom Original 400/400 Now ZZ454/4L80E/Edelbrock Pro-Flo 4/3:73 Eaton Posi PS PB and cold factory air Early Classic 4.5/6 Front 20X8.5 Riddler 4.75 inch bs Pirelli 255/40/20 Rear 20X10 Riddler 5.5 inch bs Toyo 295/40/40 Rear end is original wide 6 lug converted to 5 lug Last edited by 2500HD; 04-15-2020 at 05:01 PM. Reason: .

04-17-2020, 03:12 PM	#4
2500HD Registered User Join Date: Aug 2005 Location: DFW Posts: 268	Re: Anybody running a 4L80E trans behind their bigblock? Factory big block trucks came with the high hump so you are good there. I used a CPP cross member. If i recall i had to drill 2 holes per side in the lower frame rail. If you use the factory cross member you will have to drill hose in the upper and lower frame rails. Really isnt a big deal the holes are 7/16 i think. I assume you have a two piece shaft. What bearing do you have? this is a good time to change to a single shaft. Are you lowered or factory height? __________________ 1970 Custom Original 400/400 Now ZZ454/4L80E/Edelbrock Pro-Flo 4/3:73 Eaton Posi PS PB and cold factory air Early Classic 4.5/6 Front 20X8.5 Riddler 4.75 inch bs Pirelli 255/40/20 Rear 20X10 Riddler 5.5 inch bs Toyo 295/40/40 Rear end is original wide 6 lug converted to 5 lug

04-17-2020, 05:23 PM	#5
ImNoSpaz Registered User Join Date: Sep 2012 Location: Sparks, Nevada Posts: 108	Re: Anybody running a 4L80E trans behind their bigblock? I have the low hump and had to fold over the seam at the bottom of cab/tunnel to give the trans a little bit more room. I also tried the aftermarket trans cross member but was not willing to drill holes, so I made my own. I have the 7.4 vortec with the 4L80e, and used the Ron Francis wiring kit. That's all that was available at the time of purchase. Driveshaft, if I remember right was a 3" aluminum out of a little 80 something c10 and was the perfect length.



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