The maximum RPM the Packard V8 will turn depends upon the camshaft, lifters, valves and springs used. The OEM engine will not reliably turn 5,000 RPMs. The valves are long and heavy, the springs are weak and the hydraulic lifters will pump up. Every manual transmission '56J I have ever torn down showed damage from at least one dropped valve.

With lighter valves, stronger valve springs, a good science roller camshaft, there is no reason a Packard V8 can't turn 8,000 RPMs. I'm building on one with these parts as we speak.

The late Steve Williams raced a stroker Packard V8 and told me he turned 7,500 RPMs. The camshaft he was using was so radical it would not idle below 1,800 RPMs.

As far as the GM ball-and-stud rocker arms, no serious racers use these any more. Today's GM racers spend big bucks with Jesel for shaft-mounted rocker arms. Packard and Studebaker got it right the first time.

When adjusting the pushrods, one hand is holding two wrenches, the second hand is turning the adjuster and the third hand is holding the feeler gauge.

thnx, jack vines

The 374" block can be safely bored to 4.250". The standard cast steel crankshaft has hollow throws. If it is a street engine and not to be run hard, it can be welded and offset ground for another 1/4" of stroke. I don't recommend it.

There were a very few, very rare forged steel crankshafts made for service replacements. They have solid crankpins and can be welded and offset ground up to 3/8". Any of these stroker options will require clearance grinding of the bottom of the cylinders and relieving the bottom of the oil pan.

As to the weight of the Packard V8 versus the Studebaker V8; I weighed a 1956 Power Hawk 259" Studebaker V8, complete with bell housing, flywheel, clutch and a 1956 Golden Hawk 352" Packard V8 equipped the same way. They were weighed on the same scale hanging from a hoist on the same day.

Please go to the '56J site http://www.1956goldenhawk.com/ and read the '56J front end weight bunk article also, note the published shipping weights. The '56 Golden Hawk was only a few pounds heavier than a similar equipped '56 Sky Hawk or '57 Golden Hawk. There are two differences I have noted which make the '56J a bit more nose heavy. The Packard engine is longer and taller than the Stude and thus the weight sits slightly higher and farther forward. Many '56Js were also equipped with the Saginaw power steering, which adds another hundred pounds high and to the front.

I've owned and driven hard both the '56 Sky Hawk and Golden Hawk. The Golden Hawk will definitely accelerate faster, has a higher top speed and will keep up in the turns. Neither is a sports car, but both were the fastest cars of their day. The '56J with manual transmission was quicker and faster than the '56 Corvette and '56 Thunderbird. It was quicker and about even on the top end with the '56 Chrysler 300.

thnx, jack vines

FWIW, several Packards have been stroked to 3.75" and a few to 3.875" It does require grinding clearance notches to the bottoms of the cylinders.

It is pretty standard practice to modify the bottoms of the cylinders for a longer stroke. When Ford increased the stroke of the 289" to the 3" of the 302", they shortened the bottoms of the cylinders to clear.

IMHO, the small Packard engineering staff did a pretty good job man-for-man as compared with GMs thousands of engineers on the Chevrolet V8. It had as many teething problems in the first couple of years as did the Packard.

Another FWIW, the Packard V8 is tall and wide, but not as heavy as many make it out to be. Studebaker and the early Mopar hemis were the worst offender in terms of pounds-per-cubic-inch. The 374" Packard V8 weighs 705# ready to run, or 1.88#/cu.in. The Studebaker 289" weighs 695#, or 2.4#/cu.in. If one really wants to get porky, the Stude 224" and the Dodge 241" weigh 3.1#/cu.in

thnx, jack vines

Hi, Craig,

I have noticed only two versions of the cam retainer plate and spacer. Can you give me part numbers for the three?

thnx, jack vines

The only Caribbean I have ever seen with a manual shift was owned by the late Steve Williams. The conversion was done by the San Francisco Packard dealership. It looked strange, as they kept the wide power brake pedal and added the standard clutch pedal from a Clipper. The conversion was done because the long-time Packard customer kept blowing up the TU racing Cadillacs.

thnx, jack vines

Greetings,

The Packard V8 has a 5" bore spacing, the same as the 500" Cadillac. It would easily have grown to 500" and then some.

thnx, jack vines

FWIW, Iskenderian pushrods were actually made by Smith Brothers, who are still in business and will make anything you want.http://www.pushrods.net/ I have three sets of NOS Iskenderian adjustable pushrods I found when visiting with Ed. They are long, heavy and require three hands to adjust them. Not a viable solution for most problems.

thnx, jack vines

Hi, Eric,

The center hole on this one is only 2.5" instead of the Packard V8 3.125". If it had fit the crank, it would already be back from the machine shop and on an engine. I am building a 374" for my Studebaker 3/4t, so a lot of flywheel would be good to have there.

Asking for your input on this truck engine, I am boring a 352" to 374", with good, used stock pistons, using the '55 camshaft which has shorter timing and '55 heads, which have smaller intake valves and a combustion chamber slightly better squish and low speed burn characteristics than the '56 cam and heads. Should pull well and have as good fuel economy as is possible with a 374" in a truck. What do you think?

thnx, jack vines

Hi, Eric,

The same thought had occurred to me. It would require enlarging the center hole, drilling six new bolt holes, which are not symmetric pattern, turning down the exterior diameter and shrinking on the ring gear. The sucker weighs 43#, which would give one hell of a launch.

I'll check to determine if the dimension from the crankshaft flange face to the clutch face is close enough to the Packard V8 dimension to match up.

thnx, jack vines.

Greetings, V8rs,

I was sold a flywheel which, "guaranteed, it came off a Studebaker or a Packard V8, cause that's all Dad had." It doesn't seem to fit either. Would appreciate some help identifying this flywheel:

15.5" diameter
184 teeth
2.5" center hole
4.5" bolt circle
2.125" c/c
43# weight
drilled for two different clutch covers


thnx, jack vines