351w NV4500 converstion from a stock 302 C4 Questions

[Tankguy81]

Any one done this yet? I'm considering a C6 with 351 to dana 20 or an nv 4500 351w dana 20 or np205.

I know Bronco graveyard sells what they claim to be a complete kit but they dont supply clutch linkage and I dont know if the 351w will interfere with the linkage? I dont have any of the linkage

Kit says it requires some firewall and trans tunnel modifications, any one know the extent they are referring to?

Any advice would help a ton. Or if any one located in the south bay area (near milpitas) that might be interested in assisting for beer/other monetary incentive I would greatly appreciate.

[CityHick]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

I am no help on the C6 topic - a small block C6 should bolt right up to the back of the 351W, unsure about how easy it is to connect to the Dana 20 or the NP205, if either requires an adapter I would not spend a lot on it... neither is the greatest transfer case in the world in terms of gear ratios, and in the case of the D20, strength (at least in stock form).

The 351W itself bolts right into your existing 302/289 motor mounts. Exhaust will have to be "adjusted" as the 351w is a bit wider and taller. Meaning any existing exhaust manifolds or headers will have to be dealt with if you still have the old exhaust system intact in the vehicle.

Do you have any body lift? I have been told that there are firewall interference issues with no body lift, with the 351. If no body lift, depending on your induction choice (carb vs EFI) you may have hood clearance issues. I started with a 4bbl QJet and drop base air cleaner which cleared the stock hood by less than an inch (with a 2" body lift). Now with EFI overall hood clearance is improved slightly (top of upper intake manifold sits slightly lower than the top of my old air cleaner).

351W clutch bracket is no big deal. Old 302/289 blocks had a flat spot machined into the block for the clutch equalizer bracket to bolt to. 351w and late 302/5.0 blocks don't have that spot but its nothing a grinder can't "create" for you.

If you do go EFI, 14Justice (who lives near you) and I (in Livermore) both somewhat recently set up Ford EFI on our 351w engines. Both of us were going through the process at about the same pace and both of us can probably answer any questions you may have on that topic if you go that way. I'd highly recommend EFI especially if you are going to be doing any high elevation 4-wheeling.

There is talk of a South Bay gathering happening somewhat soon... I'll probably attend with my Bronco. Usually at least a few show up.

[pippinmader]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

Everyone has their own opinions, but I think the ZF-5 is a good and cheap alternative to the NV4500. You will have to set it up with a hydraulic clutch but a NP205 will bolt right to it.

http://classicbroncos.com/forums/showthread.php?t=25931

[Efibroncoman]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

The ZF S5-42 is a great transmission but it is also long. IIRC the NV4500 is around 4" shorter in length which works better if your wheelbase is stock. Plus you'll need an adapter for the bellhousing and for the transfercase unless you go with an aftermarket case. The ZF is 31 spline so bolts right to any full size Ford transfercase or aftermarket case. You will most likely have to modify the transmission tunnel for either because of the height. Both can be had cheaper but will take some searching. They are getting harder to find. Buying a reman isn't a bad option either- at least you know it's going to work.

[Tankguy81]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

Soo many choices...

Im kind of leaning towards the nv4500 kit from Bronco Graveyard, I guess it has an adaptor to the Dana 20, and I could use a hydraulic clutch kit from McLoud.

When is the Bronco gathering going to happen? Please keep me posted!

CityHick-What EFI system did you use? I have a 1970 351 with Vic jr heads, and a big nasty solid roller cam .621 lift intake, came out of my mustang. Any ideas on a good kit for that motor? I heard EFI kits and computers on tweeked nonstock motors are hard to tune and the computers tweek out?

[Efibroncoman]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

That would be very hard to tune! EFI cams usually have a lobe separation of 114 or higher. You can get a 112 cam to run but not as smooth. What you're describing is probably 110. It can be done but you're gonna spend some money on the tuner and do a lot of data logging!

[CityHick]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

CityHick-What EFI system did you use? I have a 1970 351 with Vic jr heads, and a big nasty solid roller cam .621 lift intake, came out of my mustang. Any ideas on a good kit for that motor? I heard EFI kits and computers on tweeked nonstock motors are hard to tune and the computers tweek out?

I did not use a kit per se. My 351 started out as a carb'd Ford crate motor. Pretty mild engine, 250hp/350 ft-lbs torque. I swapped on a Ford Lightning lower manifold and Explorer upper manifold (both are GT40 style). The Lightning lower manifold is a rare bird and you have to search a while to find one. They are all used, ebay prices are ridiculous. Mine came out of the local Craigslist for quite a bit less.
My Wiring harness is from Summit Racing (Part number sum-890120), I run an A9S Mustang computer, Explorer rails, 19lb injectors and all the various sensors, etc to make it all work. Sounds like a mixed bag (and it sort of is) but all is compatible and mine runs very well.

The stock computers that "tweak out" with radically built motors are older speed density systems. The Mustang computers (roughly 89-up 5.0 application) are Mass Air which is a bit more forgiving without a custom tune. This being said when you get a little too far out in the weeds with radical cams, super high flow... you are in custom tune territory.

I have never had mine analyzed on a dyno (and that's something I want to do). 19lb injectors are rated for 250-275hp applications and I know I am on the borderline. Bigger injectors will either require a custom tune or a calibrated MAF to "trick" your computer.

I think this is all more than you were asking... it took a long time for the EFI guys on this site to convince me but looking back I can't believe I stuck with a carb for so long.


...not sure when the gathering is happening.

[Tankguy81]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

I have a pretty radical cam with some high flowing heads, motor should put out around 450-500hp at the motor. Either of you heard or seen any one do an efi with that much power and have it work well? Ive heard a Fast EFI set up will be ok for that power rating?

[Efibroncoman]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

The question you need to ask yourself is: "How much money do I want to spend?" It is possible to get that engine to run as is... However, finding a different cam will make it much easier. I'm pretty sure even injected LS race engines that make 500-700 HP use cams that have 114 degree lobe separation. What are you going to use the Bronco for? If you have a 500 HP radical engine, it's probably not going to crawl well in the rocks. What is the compression of that engine? If it's high compression, you might wanna look into propane like the Pacific Northwest Bronco guys. Propane engines should have around 11:1 compression. Propane will be much cheaper and easier.

[CityHick]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

I too am very curious what you plan to do with this Bronco. I like a nice smooth idle in mine because my 4-wheeling style is slow and controlled (rock crawling mostly). You are putting a fire breathing monster in your rig so I am guessing this is a street rig or maybe something like a desert racer or sand dune rig.

Jacob nailed it above... how much money do you want to spend? A less radical cam would make EFI a lot easier but you might get some better input on injecting an engine like yours on a Mustang forum... perhaps find a local shop who does that kind of thing and ask some questions there. Most of us here run much tamer engines!

[Tankguy81]

Re: 351w NV4500 converstion from a stock 302 C4 Questions

Looking for an all around bad ass rig eventually. Looking to crawl, drive on the street, rip through some mud, camping, etc. This motor came out of a mustang I had and it was daily driver capable.

My only other thought would be to run an EFI 5.0 but buying used engines is sketchy to me. Ive never worked on an efi motor myself let alone try to wire one in.