High compression pistons

[BKW]

It wasnt a cj just a reglar 428 and the block is cracked in two cylinders and two rods are gone ill go take a couple pics of em theyll be in my gallery. The crank is good but im hangin on to that for a 410 in the future. I also like the power that the 428 heads give me instead of the 390 heads. Them heads are just sittin in the garage for somethin else.

What 428 non CJ heads are different than 390 heads?

The head used on 1967 428 Police Cruiser's.

Otherwise the same heads used on 390's were used on 428's...and in 1968/70, the same heads were used on 360's.

 

[TexasNomad]

Bill what exactly is a Cobra Jet head and can 428CJ heads be used on 360/390's?

 

[1985 Ford F-150]

The 428 heads are 64 or so and have the large intake ports vs the 390 that are 71 or so and have the small intake ports.

 

[SuperCab]

360, same bore as a 390 (4.05"), the 360's stroke is 3.50" / 390 = 3.78"

Difference between the 360 vs the 390: Pistons, connecting rods and crankshaft.

Everything else is the same.

So the pistons are different in the 360 even though the bore is the same?

 

[BKW]

The 428 heads are 64 or so and have the large intake ports vs the 390 that are 71 or so and have the small intake ports.

1964: Sorry, that's impossible as the 428 was introduced in the 1966 cars.

The C6 was introduced at the same time.

When you bought a new 1966 T-Bird or Galaxie/LTD with a 428, the C6 was the only A/T available with this engine.

As original.

C6AZ-6049-D .. Cylinder Head-Use before 11/8/1965 / Fits: 1966 390/410/428.

C6AZ-6049-AB .. Cylinder Head-Use after 11/8/1965 / Fits 1966/67 390/410 & 428 (except 1967 P/C) / Fits: 1968 390/428.

Midyear 1968, Ford replaced both these early heads with C8AZ-6049-M for use as a service part replacement. Service Parts-what are sold at the dealers parts counter.

The C8AZ-M head was also used on 1968/71 390/428 cars and 1968/72 F100/350's w/360/390's.

Info sources: 1960/68 & 1965/72 Ford Passenger Car Parts Catalogs / 1964/72 Ford Truck Parts Catalog.

 

[Moto Mel]

An easy rule to remember is the more compression you have the more power you will gain. Higher than 10 to 1 starts generating a lot more heat and you will have to make sure your cooling system and internal engine parts can handle it. A few years ago NASCAR teams were running as high as 22 to 1 but they must have used knock sensors and computor controlled timing for advance/retard.
A really high compression engine will have a lot of "snap, crackle and pop" when you hear it with an open exhaust. Much like a fuel dragster or a 2 stroke motocross bike.