Best manual transmission for 302

[chilidip65]

Curious which 5 speed transmission is the best match for a 1977 Bronco. AX-15 or is something else better?

 

[rguest3]

I have done the NV3550 conversion with a 347 and it worked out great!

 

[Broncobowsher]

It's not so much which transmission for which engine, it should be which transmission for what use. Are you looking for something a bit sporty and car like, or perhaps you want a really low granny first gear but still have an overdrive? Both can be had as a 5-speed but will drive very differently. That's the difference between the AX15/NV3550 and the ZF/NV4500 options. That's without going for the middle of the road low cost option of the Mazda M5R2.

They all work wonderfully behind a 302, but they work very differently depending on what you want them to accomplish. There is also the matter of the axle gearing, which generally isn't correct for adding an overdrive. Very rarely will the axle gearing already be correct for adding an overdrive and have it work correctly.

 

[1970mule]

well I will agree what was said from broncobowsher, but since I put in my nv3550 in I love it like a whole different truck. I have 302 ho efi and 4.11 gears with 33s. so it is right where I need it to be low and OD good on the highway.

 

[roundhouse]

I have a 3550 and love it !

liked it so much we installed a NV3500 in my sons 77 chevy K-10

 

[hyghlndr]

NV4500 would be my vote for the best.

 

[MarsChariot]

NV 3550 with 4.11 rear in 5th with 9.50x30s is like a C4 with 3.50 and 33s.

 

[jmangi62]

I did the nv3550 swap behind a mildly built 302,still building my rig so haven,t driven it yet,but man I can't wait,good luck.

 

[sykanr0ng]

My choice is the ZF5, in fact I bought it before I bought this Bronco knowing that it is what I want.

I will need to change the ring and pinion gears, but that was in the plan from the beginning.

To be able to have a decent crawl ratio and decent performance on the highway with one Bronco also is the goal.
Drive it to the trail and drive it on the trail.

 

[blubuckaroo]

I haven't tried the others. I picked the NV 3550 mainly because it was already a successful tranny in a lot of Jeeps. Now that it's in, it pulls my camp trailer great and will cruise at 80 MPH too. If I had wanted a crawler, it would have been a booboo.

 

[SoCal68Bronco]

I did the nv3550 swap behind a mildly built 302,still building my rig so haven,t driven it yet,but man I can't wait,good luck.

I'm in the exact same boat..

 

[roundhouse]

The 3550 has a 25% better crawl ratio than the stock 3 speed 4:1 first instead of 3:1

 

[sykanr0ng]

The ZF5 has a 5.72 first gear and second is 2.94 which is very close to the Bronco three speed which is 2.99

 

[NYLES]

ZF it!..................

 

[hucklburry rev2]

I went ZF as well, no engine adapter, just to the D20, or you can run an NP205 with different issues but no adapters (heavy).

The three mentioned are the best routes to take, all have positive and negatives, but all nicer than the three speed.

 

[roundhouse]

If you rockcrawl alot use a ZF

If you drive it on the street , dirt roads , or mild trails most of the time I'd use the NV

If you were near Atlanta I'd offer you to test drive a NV3550 and see what ya think

It's perfect on the street. absolutey perfect
At least I think so with my 302, 4.11 axles and 33's

And better on the trail than the stock 3 speed. Just not as good on the trail as a ZF

 

[Timmy390]

Man, All this ZF talk has got me reconsidering my plans for the NV3550 upgrade. The money saved on not needing an adaptor is pulling on my budget strings.

Is there a way to keep the stock clutch setup with the ZF? I really don't want to convert to hydraulic.

Tim

 

[NJBronco]

Still building mine but I went with tge mr5d. More because it's was rebuilt and free. Can't go wrong there. I just need the snow to melt so I can get back to putting up the tent and get my bronco back in there. I'm getting cabin fever

 

[sykanr0ng]

Man, All this ZF talk has got me reconsidering my plans for the NV3550 upgrade. The money saved on not needing an adaptor is pulling on my budget strings.

Is there a way to keep the stock clutch setup with the ZF? I really don't want to convert to hydraulic.

Tim

Not with the small block ZF5, it uses an internal hydraulic throwout bearing there is no clutch fork.

 

[Timmy390]

Not with the small block ZF5, it uses an internal hydraulic throwout bearing there is no clutch fork.

And that's my hang up on the ZF.......I guess after my engine build I need to dig into the hydraulic conversion.

Tim