I am a little unfamilar with this engine and I just bought the car. I'm looking to see what my options are to add more power. I have Hooker Headers and exhaust and a beefed up cam, but I'm not sure what size it is since the previous owner didn't get the papers on it. I also believe I still have the orig 3.25 rear. How can I check what size cam I have and the rear end without taking them apart? Any suggestions on what I can do to beef up the HP even more? I have an auto.
Thanks!
__________________
70 Mach 1 351C 4V, FMX, Shaker hood scoop,heavy duty cam, holly carb, headers, flowmaster exhaust, 3.73 rear, MSD set up with box
Sorry, but it would be difficult to determine which gears you have without taking the rear apart, and then you would need to know what you are doing to determine the ratio. Normally, you can tell if the ratio is 3:50 or above because the tach will run at or around 3 grand in high gear if it is at that ratio. Most street ratios run about 2 grand at 60 MPH in high gear.
You can try and measure the lift with valve covers off, but it might be hard to get an accurate reading.
For the rear, you estimate by counting wheel vs pinion revs.
You can try and measure the lift with valve covers off, but it might be hard to get an accurate reading.
For the rear, you estimate by counting wheel vs pinion revs.
Daniel......Isn't there a way to jack up the rear, and turning the wheels to determine the gear ratio? I have seen that posted, but for the life of me I can't remember the procedure.
Yeah its easy to tell approximately what ratio is in the rear. Put the rear on jackstands, put the trans in neutral, mark the bottom of the tire, mark a bolt on the u-joint. Turn the wheel ONE revolution and count the revolutions of the driveshaft. If it turns 4 times for one of the wheel revolutions, its probably a 4.10, if its only 3.5 turns, its 3.50 gears, if you only get 3 turns its a 3.00. It could be a bit more or less, like telling the difference between 3.23s and 3.50s but you get a general idea. 3.50-4.10 work good with the 4V, but you can also run as high as 3.00. I had those in a 72 Grande with the 4V, the thing was an animal even with the highway gears.
My 4V Clevelands liked the Comp cams 280H, but it was an old school cam. Its the largest you can run with a stock converter. Speaking of a converter, a 2400-3000 stall would wake that thing up considerably. Lately I have been running the XE series cams, they have faster ramps and seem to make a bit more power while keeping it relatively easy to tune. I highly recomend changing the valvesprings when swapping the cam. The stock ones could barely keep up with the stock cam. Go too big and you will need adjustable rockers, that is a bit more money and helps, but isnt absolutely needed.
If it still has the stock 4 barrel carb, keep it in a box someplace, but replace it with a 750 vacuum secondary Holley. The stock intake is ok, but you can do a little better and have a lighter front end with an aluminum intake. The choices for the 4V are limited and unless you go crazy with the cam and at least a 3500 stall, I would stick to a dual plane intake.
If you have points, upgrade to a breakerless ignition, you can get one from a 351/400M in a 75-80 vehicle. Pertronix and MSD make drop ins that work too. I have done the MSD kit and it works good.
Other than that, you dont have to do alot to a 4V Cleveland to make it run. The heads flow great from the factory, and the race engines actually make the ports smaller, but you dont need that unless you are making some serious top end power.
Post some pics of it, I'm always curious about other 4V rides..
aussie heads are what u need 4v combustion chamber and 2v ports for the perfect street head! www.351cleveland.net
__________________
Then said he unto them, But now, he that hath a purse, let him take it, and likewise his scrip: and he that hath no sword, let him sell his garment, and buy one.
Some 4v guys like port plates, which increase the velocity of the air thru the intake. Kind of the same effect of aussie heads for less money and labor to R&R.
__________________
How long does it take to get there??....Depends on how many cops are on the way.
http://img.photobucket.com/albums/v490/hockey6457/Picture066.jpg
1970 mach 1 351C 4V Looking to add more power
