1974 302 or 1996-2001 5.0 ?

[mnido]

I am purchasing a serpentine set up off of 1996-2001 5.0 Explorers. Is there a benefit to using the entire engine over rebuilding my 1974 302 ? I am going to use a carburetor, the EFI is to complicated for my simple brain. Be nice..

 

[Viperwolf1]

A key thing to consider is the condition of the motor. There are several advantages to using the newer motor. One is the balance is the same as the explorer balancer. It saves the expense of having the balancer re-balanced. Another is the explorer GT40 heads are superior to '74 heads. A possibly disadvantage to the heads is if they are GT40P heads (latest explorers) it's more difficult to fit exhaust manifolds/headers because of the revised spark plug location. I like the roller cams and the one-piece main seals on the newer engines. The explorer cam is a good upgrade from a stock '74 cam.

Other disadvantages: Lack of a clutch bracket bolt boss on the new motor. If you use an auto trans it's not an issue. If you use a manual trans there are bolt on brackets available to fit the newer motors. You'll need a different distributor drive gear. It needs to be a steel gear not cast iron. Different firing order to memorize.

 

[Socal Tom]

The 5.0 is a way better motor than teh 302. It makes about double the horsepower. Converting to a carb should be no big deal. ( though I recommend EFI every chance I get).
Tom

 

[slackccs]

The Explorer engine is rated at 210 HP...with the EFI. If you rip out the EFI and bolt on a carb, you won't get 210.

The 1974 Bronco 302 is rated at 135 HP. This is primarily due to the 69cc heads. If you remove the pollution control stuff, put a set of earlier heads on the rebuilt block ('69 or '70), bolt on a small four barrel you will make 225 HP easy. Add a decent exhaust system with shorty headers and you are at conservatively 240HP...and you really haven't done anything of consequence to the engine...yet

 

[Socal Tom]

The Explorer engine is rated at 210 HP...with the EFI. If you rip out the EFI and bolt on a carb, you won't get 210.

The 1974 Bronco 302 is rated at 135 HP. This is primarily due to the 69cc heads. If you remove the pollution control stuff, put a set of earlier heads on the rebuilt block ('69 or '70), bolt on a small four barrel you will make 225 HP easy. Add a decent exhaust system with shorty headers and you are at conservatively 240HP...and you really haven't done anything of consequence to the engine...yet

umm, I don't think so. The later engine has a roller cam and much better heads. The EFI doesn't really add horsepower, a big 4 barrell will get the same 210 HP out if it, it will just drive crappy the rest of the time.
The later model engine was built to much better tolerances and will probably run 250K miles if well maintained. The early engine was built at a time when US auto quality was its worst.

You can search the net and find lots of actual dyno results that have mustang and exploder engines ( basically stock) making 180 or more horsepower to the rear wheels. I challenge you to find a basically stock non-roller 302 doing the same.
Tom

 

[mnido]

I will be using a new NV3550 and had planned to rebuild the 1974 lower end, and add a Edlebrock system for the top end, heads,cam,intake,carb, and Mallory ignition, headers.. I can purchase the complete 5.0 serpentine conversion for 250.00, or the complete 5.0 for 650.00. I really don't want to get involved with EFI conversion.

 

[DonsBolt]

if you use the explorer engine, and serpentine setup you will have to go to a electric fuel pump, also not a big deal, just run a relay setup off a switched source

 

[G's Baja Bronco]

I am using a 1991 HO 5.0 and explorer heads with a large carb (750 cfm) I am keeping the stock cam and expect to get 280HP if not more due to the large exhaust and GT40P heads more efficient design and smaller chamber, plus the MAC shorties. I am building a daily driver (about 30 freeway miles round trip to work.