Is it just the cam that makes the different firing order on an HO motor, or is the crank different as well. Basically If I have a non roller HO block and want to do a roller conversion and run a X303 cam, and I just put a non-HO cam in a HO block and run standard firing order?
Do not run a X303 cam in a street driven car and do not run it with stock heads - you WILL be disappointed in the around town performance. Honda's will leave you sitting in the dust if you use the cam in a street environment. This cam is best suited for dragstrip and circle track racing and not street driving. This cam requires stronger valve springs and cylinder heads that flow a lot more than stock heads. Power band is from 2200-6200 RPM, great for the race track but not suitable for around town driving; it will need 3.73 or 4.xx rear axle gears to keep the engine running in the power band even on racetracks.
The crankshaft has the same crankpin layout for all Ford 5.0& 351 pushrod engines.
The Mustang HO computer will be needed with any of the Ford letter cams, they all have the same firing order.
Using a non HO computer with a Ford letter cam results in the fuel injector sequence timing being way out of order.
This cam must be used with a Mass Air computer & MAF from an 89 or later Mustang. It will not work well with Speed Density computers found in 86-88 5.0 Mustangs.
DO NOT BUTCHER A PERFECTLY GOOD STREET DRIVEN EFI MUSTANG BY CONVERTING IT TO CARB!!!
This car has a Quick Fuel E85 carburetor, car is only used for the 275 DOT street class. Only street driving this car does is the mandatory 15 minute cruise before the street car class race. Car has a 8.8 with 35 spline axles and spool, 4.10 gears, c clip eliminators, UPR solid bushings and braces. I am just now getting to changing cam and heads.
Another question I have is my block is a 1980, but the ford racing retro fit roller conversion says 85-01. I thought all 302 blocks were the same, why would this not work in my 80 block?
The lifter valley is not drilled for the spider that holds the dog bones that hold the roller lifters. The lifter holes are not made for roller lifters, roller lifters are taller and will not work unless you use a small base circle cam which is a whole nother subject. Use retro fit (linked) roller lifters or go flat tappet lifters.
it also helps to have as much info as possible when getting advice otherwise you get confusing suggestions.