Gearing

[crewcabshorty]

I am putting a v 30 toegether now and needing some advice . I am running a 350 motor , will be running a 4l80 , 33 inch tires . The gearing is my question . Will 4.56 s work or will they be to low for highway cruising . Thanks

[SkinnyG]

Plugging the numbers in to an online rpm calculator gives 1950rpm at 60mph. 2850 in 3rd. I'd say this is pretty decent, but I don't do any four wheelin'.

[Mattchu60]

In my opinion 4.56 is a good choice for 33's with overdrive. I have a 350 with a 700r4 (OD), 4.10's and 32's on my truck, and there are times I wish I had 4.56s. I have no issues going 60 mph with my setup, its the interstate cruising at 70 mph that gives it fits, it seems like the wind resistance increases a lot at 70 and sometimes it lugs the engine down pretty hard, driving in D at 70 revs the engine to 3k, while OD keeps it around 2100-2200. I feel like 4.56 would be the sweet spot.

[GRADYS Performance]

A 4.56 with a 4L80E in overdrive is like having a 3.42 in third gear or Drive in a TH350/TH400. Plus when the torque converter is locked up you drop the rpm lost to converter slippage.

[crewcabshorty]

Thanks for the response !

[MTCK]

That's exactly what I was running for a drive train until I swapped in my L29. 4.56 and 33's with a 350, 4l80e and these heavy trucks seem to do good. You're not going to do 80 mph all day long down the highway, but it gets around town good, pulls decent and is still pretty civilized at 65-70.

[crewcabshorty]

Thanks MTCK ! Love your build . A vortec 454 swap is on my list .

[MTCK]

Thanks it has been fun. Lots of work but at the end of it, a great motor for a big heavy truck. I keep thinking about that tire ad on the radio where they say go out there and do truck stuff, and a big block is great for that! Look at 8.1L's too. I was going that route until this motor fell into my lap.