Help me please tryin to beef up 318
okay well today iam going to take some pictures and get numbers off the car what numbers would you like and where can I find them?
If you want to grab the casting number off the engine block look on the drivers side near the rear of the engine. Rear end casting numbers might be helpful as well. If it is an 8 3/4 rear the casting number will end in either 741, 742, or 489. A '73 Dart never came with an 8 3/4 though so there's no telling what you've got especially when the word "custom" gets thrown around.
If you want to figure out what gears you have, look for a tag on the rear end with a gear ratio stamped on it. It should be on one of the bolts on the center section. If there's no tag, jack the rear end up so the tires are off the ground, put the transmission in neutral, and spin the tires 10 times. Count how many times the driveshaft goes round 'n round for every one time the tire goes full circle. If the driveshaft spins 32 times you've probably got 3.23's, if it spins 35 times you've got 3.55's, etc. It's not too hard to figure out. Your other option is to count the teeth on the ring and pinion but that's the hard route to go. Lol.
What transmission do you have? You say four speed. Auto or manual? It makes all the difference. Casting numbers would help here and so would pictures.
You've got some time to plan this all out so figure out the parts that are already on the car and it'll be easier to figure things out from there. The first step of getting where you want to go is to know where you already are, yeah? Pictures help too, the more the better.
I graduated HS in 2013 and worked on my car a lot through high school. It took me until freshman year of college to finally drop a V8 in it. The 318 I built was pretty mild and it was fairly peppy. It could have used some deeper gears than the 3.21's I have in my 8 1/4. I had a '68 318, stock bottom end, 901-16 valve springs with otherwise stock heads, a Comp HE268 cam, true roller timing chain, Melling Std. vol oil pump, Clevite bearings, Edelbrock Performer intake, 600CFM Edelbrock 1405 carb, 1/2" carb spacer, Hooker Headers, and had Flowmasters dumped at the axle. It ran pretty good for what it was.
I think you could build it up to take on a 5.0 depending on what year the Mustang is. Those Mustangs can be pretty quick but a hopped up 318 could give it a run for it's money I think. If you are still slower than him after doing some upgrades over the winter......nitrous.... :burnout:
