I bought a 427 that came out of a 2 ton truck, to go into a chev 1/2 ton pu. What I am wondering is what is the differance between a truck and a car 427? Are they both cosidered rats? How do I tell what I have for sure? And what makes it a rat? Is the 427 really the real rat engine? If not what makes a rat a rat??!!??!!??!

 

To my knowledge rat just means its a bigger CI motor like a 400 or so. I would think the difference between a truck and car 427 is the cylinder heads. The truck will probally have larger CC combustion chambers and smaller valves, and the bottom end will probally be made stronger, like a forged crank and what-not. The reason for larger combustion chambers is lower compression ratio so lower grade gas. And the smaller valves cause the motor won't be turning many rpms so it only needs to concentrate on flowing well on the low end(motor makes more torque and is more torque based with the smaller valves. Thats your best bet is to get the stronger 427 truck bottom end and find a good set of heads that are made more for top end.

 

the 427 truck engine block is differantfromthe car engine block (this includes pickups also). The truck engine uses taller pistons & therefor has a taller deck height on the block (something like a 1/2 inch) which causes the "V" to be wider on the top of the engine. This causes many parts to NOT interchangewith the car engine & they usually do not fit well into car chassis. You will rarely see these being used in performance aplications. Might work in the pickup however. If you build the motor make sure your parts supplier & machine shop know what you got! A cousin of mine who runs a performance engine shop says they make good boat anchors.

 

If you ever want to buy parts for it just make sure you include the fact it came out of a 2 ton

 

The truck 427 uses a different cam and heads to produce more low end torque.
The car 427 has a cam and heads that are designed to make high end horsepower.