Hello, just looking for some advise. I have 2 f100's that I would like to use to make 1 good truck. I have a 1979 and a 1974. My question is what will interchange and what will not between the two models? Will the cab and radiator support on the 74 fit the chassis of the 79? Just wondering what options if any that I might have.

Thanks

 

Unlimited everything. Few quirks, read the stickies. Headlights require same support without drilling.

 

The cab will swap, LMC uses one part number for 73-79 radiator supports which makes me believe that it will swap over. The engines are different as are the mounts. Transmission transfercase should interchange.
If the 74 Front fenders, inner fenders, hood and grill are in good shape I would put that on the best truck/frame. I love the look of the pre '78 dentsides. Makes me want to swap a few years earlier of my 1978.

 

Thanks for the info. Yes the I agree, the 74 looks much better and the cab is actually in better shape than the 79 that's what I was hoping for to use the 74 cab on the 79 chassis. Both have the 302 but the 79 has all the smog crap on it that I really don't want to use.

 

If you're swapping the 302's it may be a good time to do some small engine rehab and boost performance. A complete topend kit with heads would wake that small journal 302 engine up a lot, or just cam intake headers carb kit.
I am stuck in F250 land I omit anything that reads F100 or F150 and automatically replace it with F250 sorry for the wrong engine information.

 

I used the chassis and drive train from a 75 F100 and the cab and front clip from a 78 F100 to build Cletus (see link in signature). No fitment issues. 302, 3 on-the-tree.

 

Exactly what I was planning on. Swapping the ole 2 barrel out for a 4, headers and such. Only 58,000 original miles on engine so the bottom half might go for a while. What cam do you suggest? And heads, maybe gt40p

 

Any towing cam or something that is 1200-5500 RPM


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A few things to think about when selecting a cam are what is your compression ratio going to be? Your lobe separation should be lower with lower compression and higher with higher compression. With my 460 I went with 112 separation but I am almost 11:1 compression.
Next is vacuum, power brakes (if equipped) run off engine vacuum, a lumpy camshaft that doesn't kick in until 2000+RPM will not have very great brakes. Also lumpy cams are at times harder to start.
It is absolutely necessary to get new lifters with a new camshaft. It is recommended to upgrade pushrods to a hardened set too. Push rod/ rocker geometry will make or break your top end. If there is too much lateral movement of your rocker to valve, you will wear out valve guides quickly.
The above camshafts are basic broad-range suggestions. You need to do a reality check of what RPM you will be at mostly, how high you plan on revving the engine and where you want your torque. A GT40 head is a great option!!! Low cost and better flow. Note the CC of the head and do a computer compression ratio. Your pistons will be stamped with a number and you can get the +/- CC factor with that and get a more accurate computation.
Most camshaft manufactures have an excellent helpdesk to help you chose the camshaft to fit your build and are easy to talk with. Or go talk to your local engine builder.

 

LMC doesn't have a friggen clue! There are THREE different radiator supports, TWO for 1973/79's with round headlamps, ONE for 1978/79's with rectangular headlamps.

1973/79 F100/350's with the super cooling radiator (26 1/4" wide x 24 11/16" high) and round headlamps:

The radiator support has a larger opening radius than the standard/xtra cooling and A/C radiators (26 1/4" wide x 19 3/4" high).

 

Thanks for the info. Very detailed, I will definitely use your advice and do my homework before starting the engine build.