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Discussion Starter · #1 ·
Just trying to choose a cam...I'm getting a low mileage rebuilt '70 302 for my '65 Mustang from a local guy. I've heard the engine run in his '67 fastback, but it has a Comp XE274 in it (he has 3.70 gears and a 2500 stall converter). I think I'm going to decam it some because my Mustang has 2.79 gears and a stock C4. This 302 has '70 351 heads (1.84/1.54 valves), he said they're just cleaned up a little, 9.0 compression, and long tube headers (not sure of the size). My car's got 25.5 inch tires (or so)...I don't really care how fast the car is, just want it streetable with a little oomph. Any ideas on a good cam for my needs? Thanks!
 

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Here's what I tell people when choosing a cam. Call the manufacturer. Seriously, this is what they do, everyday. I'm a Comp Cams fan so I'd simply call their tech line, give them the car specs and what your intentions are and prepare to listen. When you've decided you can order through Summit or Jegs and a couple days later it'll be on your porch ready to install.

John
 

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Discussion Starter · #3 ·
I talked to Comp (which I had planned on doing, just got a little impatient for ideas this weekend), and they recommended the XE262H. Does anybody know what effect I could expect if I tried advancing the cam 4 degrees for a little more lower end with the XE274H?
 

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Here's what I tell people when choosing a cam. Call the manufacturer. Seriously, this is what they do, everyday. I'm a Comp Cams fan so I'd simply call their tech line, give them the car specs and what your intentions are and prepare to listen. When you've decided you can order through Summit or Jegs and a couple days later it'll be on your porch ready to install.

John
:bow: AND HE CAME DOWN FROM THE MOUNTAIN... :bow:

This is the most sensible post I have read here in some time.

As far as advancing the cam, you would really need to run it straight up and then advance to see if it helps/hurts.
 

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Yep, if it was me I'd leave the cam and change the gears.
 

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Discussion Starter · #8 ·
I drive on the freeway too much to change gears, plus I'd have to buy a traction lock differential, which I don't really want or need. I think I may go with an XE250H or maybe an XE256H. They're pretty tame. I wasn't planning on a new engine, and I just had the transmission rebuilt last winter; it has a 24 spline input shaft, no shift kit, and is setup to shift at 4500 RPM or so. The driveline just isn't set up for going too quickly, so when I say a little extra oomph, I'm not looking to run 13s or anything. Something that could run high 14s or so would be fine, and that's just a guess, because I'll never drag race it.
 

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a gear change would be the only way with a 302 , for his "little oomph"
Yep, if it was me I'd leave the cam and change the gears.

2.79 gears . get a stock replacement cam
See a pattern developing here? :eek: With a 2.80 and stock drivetrain anything much over stock is probably gonna make it worse, not better. Even a 3.50 gear set (you don't really even need posi for your use) would be a much wiser choice for you I think. If you go with a larger cam first, I haven't much doubt that you'll be forced to re-gear it later or swap the cam back. Go too big and you'll be making a converter swap as well. Trust me, I know from experiance. Everything MUST be set-up to work together or everything fails.

I once ran a set of 3.00 gears in a '66 Fairlane that I had dropped a 550+ HP 428 in and it was a dog unless you were rolling along at 30 MPH. A simple fact that the cam was too big for the car's set-up. I know you're not a drag racer but for reference it ran 14.00 et's at the track but would easily beat an 11 second car on the street from a slow roll. Horrible botton end was the result.

John
 

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I question the compression figure. A 70 SB without decking or DOOE heads without milling would have more like 8 to 1 maybe less Been a while since looking up the figures started to use that as a basiss for build turbo build long ago.
Those heads flow more than the stock ones so even with a stock factory cam some power would be had do to the heads.
 

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Discussion Starter · #12 ·
I question the compression figure. A 70 SB without decking or DOOE heads without milling would have more like 8 to 1 maybe less Been a while since looking up the figures started to use that as a basiss for build turbo build long ago.
Those heads flow more than the stock ones so even with a stock factory cam some power would be had do to the heads.
The engine has flattop pistons, and the heads have been cleaned up, so I assumed they're milled a bit. I got the specs from the current owner of the engine, and he worked with my local machinist on the build.
 

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I had a 70 Mustang 302 with a Crane Fireball cam in her with stock heads, dual plane high rise, 600 holley, headers and a Mallory distributor. My C4 was basically stock except for a 2500 rpm converter and shift kit. I loved the set up except for the 2:79 gears in the rear....it was a turd off the line but like others say no real power till you got around 30 mph then it was great. I never did get around to changing the gears out to 3:50 since a valve broke and that was the end of that motor. To bad but I won't do that set up again with 2:79 gears or 3:00 gears which is what I have in my 66 Fairlane. I would do the gear change first and see how you like it, then if you really want more power then I'd check the compression and if it's low then I'd change that to a better compression.
I'm in the same boat your in with my 66 and I plan on doing everything else before I even put a cam in the 289. I plan on putting 3:25 or 3:40 gears in and then recurve the distributor. Right now I've got a dual plane high rise, 500 cfm Edelbrock, headers and pertronic module in my stock distributor and I do highway driving too and changing out a stock cam is the last thing I plan on doing.
 
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