Hi Guys. My son and I built a 78 f150, 2wd and he has driven it for about a year. We have decided its time to swap the extremely tired 300 for a little more HP in a decent 302. From other threads it seems like I need to get some new engine towers and a flywheel that is balanced for the 302, new radiator, etc.. I have one more question though regarding the drive train length. (The tranny is a RUG, 4 speed by the way.) Will the length (position) of the 302 when its mounted up require me to move the cross member or mount of the transmission or will it require a new driveline? Thanks for all of the help on the project guys.

 

RUG SR-OD Single Rail 4 Speed Overdrive ~ 1978/83: 300/302 F100/150 2WD, E100/150 and misc 200/250/302/351W Passenger Cars.

You may not be too happy swapping in a 302, as from this era, it was gutless turd with barely enough torque to pull a sick trollop off a porcelain device!

IMO, you'd be better off keeping the 300, instead of searching and swapping in a 302 and related parts from gawd only knows what.

 

Thanks for the advice. The 302 is out of a 71 f100 and we are going to swap the 2bbl carb for a 4bbl and put headers on it as well for a little added power. Do you guys think I should hold out and search for a 351? Anyone know the answer to the original question about tranny position and driveline length for either of these motors? thanks again.

 

Measure? I think you're over thinking this..... Moving the x-member only requires two holes to be drilled if needed.

 

Thanks for the advice. If I have to move the crossmember will that impact the appropriate length of the drive line? What is your opinion on HP in the 71 302? All I know about the motor is that its got the same compression (160 to 165) in all 8 cylinders. Will a 4bbl carb plus headers get me 180 or 200 hp? thanks for the vote of confidence -- this will be the first time I have done an engine swap.

 

First, what tranny does the truck have now?

If the difference is an inch or so, the driveshaft might be okay. What you want to check when the time comes is that the slip yoke is
half way into the trans with the vehicle at ride height to account for suspension travel.

Contrary to what the parts guy stated above, a 302 with a few upgrades is OK. It is relatively underpowered when towing IMO. Given that your kid drives it, it's prolly better that it's not a tire burner.

 

If you have a OD rug transmission you have found a real gem. Those suckers are expensive and hard to find.

To keep with that tranny you will need a small block bolt pattern. A 302 will fit, but you probably wont be happy with the power. What power they do make is not well suited for a heavy truck (with the aerodynamic properties of a brick). Hold out for a 351w and build that up a bit.

 

Definitely better that its not a tire burner and this truck will be doing zero towing. It has the 3 speed plus overdrive RUG manual transmission. The rear end is geared at 3.00 so the current combination of tranny and tired motor make it a real dog as its set up now.

 

Have you considered building up the 300? They can be stout engines that are darn near bullet proof.

 

Yes, I have thought about building up the 300 but I think there are more options with a 302 and he is going to be driving the truck while we are working on the motor. We planning on taking a few months working on the motor while its on the engine stand and then do the swap over a weekend to have him back on the road.

 

I had a 76 with a 302 and it was OK.. it even managed 17 mpg. However, towing was a real chore and it was a total dog up hills.

I've got two of them OD transmissions languishing under my deck.' 'got em for nothing from my neighbor who scrapped his 81 F150 through the air district who pays ya $750 to turn in older vehicles. He had over 400K on his 300... he's really meticulous with his vehicles.

 

IMO, it's more like a germ than a gem! The RUG is a "weak sister" as it was original designed for 200/250 I-6 cars.

FoMoCo began installing the RUG in E/F100/150's in an effort to improve MPG after the first Arab Oil Embargo ended.

Another Arab Oil Embargo occurred in 1979. All the RUG parts are obsolete and expensive when found. The F100/150's shift lever fits into a nylon bushing that's notorious for cracking apart.

When this occurs, you aren't going anywhere until you can find a replacement.

 

I never knew RUG transmissions had such a bad name! From what I have read they were an OD option which helps out for fuel economy, which makes sense with what NumberDummy said about oil embargos. Were they made with weak parts(nylon bushing)? I have looked into various OD swaps for the NP435