new guy needs some help

[80turd]

Ok i am new to the scene. I just inherated a 1980 F-100 Custom 4.9 inline 6 300, 3 speed auto.The body is in sad shape but them engine only has 56000 original miles on it. the truck sat from time to time and its last time sitting was for about 4 years. I have just redone the brake lines because they rusted through, it has new tires and just rebuilt the carb. One of my lifters is making a pretty loud knock, i am going to change the oil and throw some 10-30 in to see if it helps at all. i have 2 questions.

1)from the info given can someone tell me what size gas tank i need for a replacement. i filled it with gas and the next day it had 3/4 and today it had 1/2 tank and i have only driven 30 miles. I also located a nice size stain on the driveway that i hadnt noticed until now because of the rain/snow.

2) With the info given can anyone tell me what trans this truck has? i want to do a flush and went to get fluid and the gay said there are 2 different trans one was somthing along the lines of a c4 and the other a c6?

 

[bronc76]

Assuming its the same tranny that came with truck or had a replacement that was the same, the code for a C4 is 'G' and a C6 is 'K' located on the name plate which should be on driver door. Another way to tell is look at the pan for the number of bolts. C4 has a square pattern with eleven bolts. A C6 rear edge is S-shaped and has seventeen bolts.

As far as the fuel tank can you get dimensions?

 

[80turd]

Thanks for the help. i will check the door tomorrow. It has been cold and crappy so i have not wanted to climb under and look around yet. next day it is over 35 i will climb around under there and take a peek at what im working with.

Assuming its the same tranny that came with truck or had a replacement that was the same, the code for a C4 is 'G' and a C6 is 'K' located on the name plate which should be on driver door. Another way to tell is look at the pan for the number of bolts. C4 has a square pattern with eleven bolts. A C6 rear edge is S-shaped and has seventeen bolts.

As far as the fuel tank can you get dimensions?

 

[krafty]

fuel tank rear of axle is 19 gallons

fuel tank side frame mount is 16 gallons.

the type of trans doesn't change the type of fluid but, another way to tell them apart is how many pieces the trans housing is.

C4 is 3 main pieces, bell housing bolts to trans housing , bolts to output shaft housing. ( the bolts are obvious)

C6 is 2 main pieces, the bell housing and trans housing are cast as the same piece, one flows into the other, with the output shaft bolted on the end.