Trans & Engine Build...Atlas???

[matt w]

i have owned my 1973 Bronco for over 25 years.

The transmission finally went out after years of faithful service, wheeling and miles and miles or fun!

The Rear main seal leaks.

I am going to have the stock 302 rebuilt as well as the transmission at the same time.

I am going to keep the stock 2 barrel carburetor on it as it has performed flawlessly all these years!

ONE ISSUE IS THAT I was having overheating issues/ vapor lock in heat and altitude when heat was a factor. Alas i never got it ironed out.
What would you recommend with the new engine to eliminate future overheating challenges,,,PS I've tried EVERYTHING EVER RECOMMENDED o my old engine...none of it worked well.

The other possible fix is adding an Atlas since it will be out.
It currently has a twin stick set up with a Tera Low 4:1 gear reduction Kit.
What Atlas T-case be recommended if i did want to swap that in as well? I want to price that out as well. I just might add that to this resurrection as well! Ha

I would like a "little more kick" out of the 302 however i need it to be a reliable trail rig like it has been for the 25 years I've pushed it! Ha

What would you recommend as far as the 302 build with a stock 2 barrel carb...would you stroke the motor? or just rebuild to stock?

Thanks,
Matt W.

 

[nvrstuk]

Q's for you-

What type of wheeling?

Upgrade axles and ujoints?

Do you like power?

Is mpg all you're interested in?



You can NOT go wrong with an Explorer 5.0 with serp. Just can't. EXCELLENT engine for a 5.0. Can't go wrong with a stroker. I like torque so much I have been building sbf strokers for decades.

The stock Exploder motor has a HUGE amount more HP than a stock 302. Get one with 170K miles and you will blown away as it will not show any wear in the cylinder bore and it should outlast any rebuild of a 302 (with stock parts, rings, etc) starting with 170K.

Atlas is nice but ... they are super expensive and won't gain you much more than you have now-except dependability. Do you have the upgraded output shaft? D20's are getting very old. Can still work fine but can't handle the abuse an Atlas can - or a 205.

Stroker - you will probably lose a couple mpg. However, if you have a 302 you aen't getting much mpg anyway so a stroker will give you a ton more usable torque and you will use it every day.

The Exploder engine helps you with a couple other issues you've had. Overheating. The Exploder frt dress with the serpentine belt and clutch fan will COOL your engine WITHOUT effort! Best setup you can install on a 5.0 or like I mentioned earlier, find a used on with all accessories and bolt it in.

You do not need to keep the EFI on it if you don't want but it's an EASY upgrade for you if you want. Check out 50 posts on here about upgrading to the Exploder engine and EFI.

 

[bigmuddy]

100% what Nvrstuk says!

 

[fordguy]

Q's for you-

What type of wheeling?

Upgrade axles and ujoints?

Do you like power?

Is mpg all you're interested in?



You can NOT go wrong with an Explorer 5.0 with serp. Just can't. EXCELLENT engine for a 5.0. Can't go wrong with a stroker. I like torque so much I have been building sbf strokers for decades.

The stock Exploder motor has a HUGE amount more HP than a stock 302. Get one with 170K miles and you will blown away as it will not show any wear in the cylinder bore and it should outlast any rebuild of a 302 (with stock parts, rings, etc) starting with 170K.

Atlas is nice but ... they are super expensive and won't gain you much more than you have now-except dependability. Do you have the upgraded output shaft? D20's are getting very old. Can still work fine but can't handle the abuse an Atlas can - or a 205.

Stroker - you will probably lose a couple mpg. However, if you have a 302 you aen't getting much mpg anyway so a stroker will give you a ton more usable torque and you will use it every day.

The Exploder engine helps you with a couple other issues you've had. Overheating. The Exploder frt dress with the serpentine belt and clutch fan will COOL your engine WITHOUT effort! Best setup you can install on a 5.0 or like I mentioned earlier, find a used on with all accessories and bolt it in.

You do not need to keep the EFI on it if you don't want but it's an EASY upgrade for you if you want. Check out 50 posts on here about upgrading to the Exploder engine and EFI.

If you want economical go with rebuilt explorer 5.0 and carb if you already have a carb and intake. If I were going to stroke I would skip 5.0 and get a good roller 351, they have inexpensive 393 stokers. Be sure it is a roller engine, no cam break in. See pics of 200k motor, the last two we have pulled looked this away.

 

[nvrstuk]

If you are going to buy a new engine don't even look back. Go 408 for the win. You will not EVER regret the torque and power that is available with it.

I got 12mpg with my 500hp 418cu in sbf stroker that was built for torque, not hp.

 

[Johnnyb]

I like what @nvrstuk says about Exploder pull-out's. The last of the 'Stang and Exploder pushrod 5.0 engines were the best of the whole 302/5.0 run.

Getting a serpentine and a better alternator (3G or 4G) were absolute requirements for me. Also the fan and fan clutch are amazing, and with a WH aluminum radiator, my temp never budges off 190, even pulling hard for 30+minutes at a time. Serpentine could be added to a stock 302, but why?

I somewhat disagree with nvrstuck about the Atlas, however. Unfortunately, my D20 rebuild went sideways and it pops out of low. I pulled and installed the D20, but had it rebuilt at a shop with a press. Now I may need to pay for another rebuild because I used non-stock shift-rails, and the shop blames the rails for popping out of low. By the time I am done, I will have more $$$ in the D20 than a new Atlas!

-JB

 

[Yeller]

^^^^^^ this is why I have 2 Atlas’s in my garage, may breakdown and make it 3…. Cry once is my theory from spending more trying to not spend it then spending it anyway because the spending more previously was more than the atlas and was still a failure.

 

[nvrstuk]

Well, Steve, you know my whole story about front ends and rear ends and everything else I've blown up trying to save money but keep it somewhat stockish. (like a 9" rear-total waste of 20 yrs! lol)

As you well know- I finally gave up on those efforts as you gently pushed me over the edge- never looking back again!

Remember everyone- a Bronco was rated as a quarter ton vehicle. About as tough as a Samari. (looks waaay cooler tho)

 

[Yeller]

Remember everyone- a Bronco was rated as a quarter ton vehicle. About as tough as a Samari. (looks waaay cooler tho)

Everyone forgets the bronco was designed to compete against the Jeep CJ2A, CJ5 and International Scout 80 and 800. All very light duty vehicles. The only things that made them robust was their lack of power. The bronco was more comfortable and the 170 i6 was more powerful lol.

 

[garberz]

Time to buy another Explorer donor vehicle.

Mark.

 

[Johnnyb]

Everyone forgets the bronco was designed to compete against the Jeep CJ2A, CJ5 and International Scout 80 and 800. All very light duty vehicles. The only things that made them robust was their lack of power. The bronco was more comfortable and the 170 i6 was more powerful lol.

I disagree, the Bronco has a fully boxed frame and a number of other attributes have led us all to continue to modify and improve these wonderful old vehicles.
It was designed as a light duty vehicle but it has just enough to build upon to have given it this cult following after all of these years.

-JB

 

[gnpenning]

While I agree with parts of most of the responses what you have described is what I will answer.

You can rebuild what you have with a couple upgrades and be happy. You can put a 5.0 in stockish form and be happy.

You can put in a stroker and after chasing the parts upgrade trail you might be happy. More power means stronger components.

Broncos were built with some decent parts that hold up well to moderate upgrades. Crossing that line all bets are off.

Some people can and apparently break anvils with toothpicks, while others rarely break anything. Add horsepower and you can join them in breaking parts.

You have done fine so far with what you have, how much more would YOU really need. Base your decision on YOUR usage.

 

[Yeller]

I disagree, the Bronco has a fully boxed frame and a number of other attributes have led us all to continue to modify and improve these wonderful old vehicles.
It was designed as a light duty vehicle but it has just enough to build upon to have given it this cult following after all of these years.

-JB

I do agree that the bronco is much better and why we continue to improve them, the bones are there. Some of us have exceeded what those bones will take but for the majority they are fantastic. But let’s face it a Dana30 and a 28 spline 9” while equal or better than what the competition was offering in the day, they get unhappy with big power upgrades and doing more than cruising in a parade. They still had 1/4 ton drivetrain

 

[nvrstuk]

The D30 & 9" die easily with a 200ci 6cyl but with low gearing, lockers & larger, let's say 35" tires.

It is not the horsepower folks. It is the traction and the torque multiplication that can be applied from the engine to the ground is what twists stuff off.

When I first when to a doubler with the ZF with the SAME engine I twisted everything in half when idling-, idling!

Torque applied from engine to trans, to doubler (maybe) to lower gears to 4 tires, not to 2 tires with the least traction but all 4 tires that are now larger tires...

THIS is what twists stuff off and why stock EB parts were good then- but not now (for most of us anyway) (couple typo updates)