How far do I need to go with this build?

[sasquatch20]

I've searched, and read a lot of build threads, and have seen how much hp different setups have yielded, but am not sure what that translates to time wise. I have a 1972 mustang convertible with 351 2V, bone stock, 2.75 gears, and FMX transmission. I plan on doing an Edelbrock performer intake with 600 cfm carburetor, 3.50 ls gear swap, shift kit, petronix upgrade to distributor with upgraded coil, and dual exhaust. I'm wondering if headers are worthwhile (not sure how well the manifolds flow) and if I need to plan on a cam swap too (and all that goes with that-timing chain, lifters, springs, etc)? My goal is to get a mid to low 14 second car, not planning on racing really but might take it to the local midnight drags at the track sometime to see what it does and don't want to be embarrassed by a civic.

 

[mach71351c]

The 3.50 gear will be your biggest gain.

 

[vozaday]

Cam will make a huge difference power wise. I was getting valve float around 5500rpm and could barely spin the single tire. That was with a 670 carb, performer intake and accel distributor. After the cam it smoked that single tire like crazy. Even when I put in the LSD it is no problem to break the tires free now. I didn't notice much difference when I put on long tube headers, but I'm sure the exhaust scavenging did help.

Gears is something I need to do in the future. I have never taken my car to the track, so I don't know what it would run.

 

[TommyK]

IMO you will need to have at least 300 HP to get into the 14's in a vert assuming a reasonable amount of traction. I don't think you are going to get there without a cam swap.

 

[Mister 4x4]

I can't and won't be able to say what mine does on a track, since I don't plan on ever racing it. Literally everything on my car was thoroughly shot, which is one big reason I went nuts with my build - gotta put new stuff in anyway, might as well go with some good stuff. Click on My Garage for my car's recipe if you haven't already - there's more in there than just engine stuff.

According to the CompCams CamQuest utility, it should be making around 400 at the crank, and that gets pared down with the automatic and 3.00 rear gears. The utility is primarily for helping select a cam, but you can also use it to figure out what kind of other things you'd need to do to get to a specific level of power.

As Mike said though, the 3.50s will be your biggest gain. They'll get the launch range closer to the power band faster - 2.75s are cruising/economy gears.

 

[Carolina_Mountain_Mustangs]

If you do a search for ET for a Boss 351 back when new you will find and ET of high 13's 13.9 @ 102 mph was what I think Car & Driver got. Most of the magazine test cars were ringers in that they were tweaked so one off the showroom floor was probably in 14's. That being said you can base engine and rear changes on the Boss specs. Compression is another way to gain HP but you have to burn the good gas then and it gets expensive.

 

[Don C]

Get this month's Mustang Monthly magazine, it has an article on the 10 fastest stock Mustangs. It'll give you an idea of what you need for mid 13s.

 

[sasquatch20]

I appreciate the input. I'm excited to get to work on the car, but think i'll wait another month or 2 until the snow starts falling here, where it'll be in the garage anyways it seems like a better time to start tearing into things, and that gives me a little time to drive it and enjoy it for now.

 

[Stanglover]

I've searched, and read a lot of build threads, and have seen how much hp different setups have yielded, but am not sure what that translates to time wise. I have a 1972 mustang convertible with 351 2V, bone stock, 2.75 gears, and FMX transmission. I plan on doing an Edelbrock performer intake with 600 cfm carburetor, 3.50 ls gear swap, shift kit, petronix upgrade to distributor with upgraded coil, and dual exhaust. I'm wondering if headers are worthwhile (not sure how well the manifolds flow) and if I need to plan on a cam swap too (and all that goes with that-timing chain, lifters, springs, etc)? My goal is to get a mid to low 14 second car, not planning on racing really but might take it to the local midnight drags at the track sometime to see what it does and don't want to be embarrassed by a civic.

This is from my most recent personal experience. DO NOT waste your money on a Pertronix III for the Ford distributor. I have first hand experience on how bad it is. Not electrically, but its construction. I have sent mine back to Pertronix with a polite but strong letter. I did however install a Pertronix II which fits exactly where the points normally fit on a standard baseplate. First though, take the plate and thoroughly clean it to make sure it is moving freely. My engine is now running better than ever after retiming and curving the dizzy. Just my 2 cents worth.

 

[71XR7VERT]

I upgraded my 9" gears with 3.30 on an aod 4spd trans. It's ok but would be better at 389 or better imo.

 

[basstrix]

I noticed you are in Utah....what is the altitude there? Altitude will play a significant role in how much you need to do to get into the low 14's. My 72 ran high 16's when it was stock. I can't remember if it was running 3.00 or the 2.75's at that time. A worn out 351 4v with a 780 holley, headers, and 4.11's brought it into the high 14's/low 15's. I was at 4300 feet.

 

[sasquatch20]

I'm around the same, between 4200-4300 feet. After talking to my brother in-law I might try to keep the gears or maybe go to 3.0 or 3.25. He pointed out that it'll be revving pretty high at freeway speeds. He's gone through this with his car not having overdrive and has 3.83's in it and red lines around 5000-5500 (around where mine will be with the intake and cam i'm looking into).

 

[basstrix]

My 72 ran high 13's low 14's with street tires, capped headers (meaning it had mufflers on it), 429 with ported D0VE heads (about 10:1 compression), hooker super comps, 850 holley DP, port-o-sonic single plane intake, msd ignition, c-6 with wide ratio gear set & shift kit, 4300 stall converter, 4:30 limited slip. It had a crower 297/308 duration hydraulic cam in it. Pulled hard up to 5000 but would redline at around 7000. (it didn't like 7300rpm when I raced a 930 Porsche...135mph was the fastest the car ever went and I was right beside a bright red 930 ) With street tires, you had to feather the throttle to maximize traction. It was a beast.

It would drop a full second in strip form (slicks, different carb, open headers with extensions, etc...).

The funny thing is, I can't count how many "12 second" cars I beat in street races