How can you tell the difference between a 5.0 TPI and a 5.7 TPI

 

Check the casting numbers on the block.

http://www.mortec.com/location.htm

 

If you mean the TPI setup itself and not the motor, I don't think there is a difference. I have swapped the TPI intakes between the two several times and it works on either one.

 

Remove a cylinder head and measure the bore

 

TPI intakes are the same for each motor

to check to see if its a Lb9 or L98, then check casting numbers on block behind the heads or in front of the passenger head, or check the cars vin code which may not always be right. A member here just the other day was asking about a cam for his 305 when he discovered it was actually a corvette L98!!

 

Man, that'd be sweet, but i have an L98 anyways.

Are there two specific casting numbers on the block? How would a person decipher the casting number?

 

there is a different type number on a 'pad' in front of the passenger side cylinder head and a casting number somewhere else behind the cylinder heads. they both can be used to tell what you have
code decipher on the net on sites like mortec.com or whatever it is.

 

or you can pull a valve cover check which heads are on the car 081=LB9 083=L98 plus itll only take a minute to do.

 

Deck stamps and head casting numbers are only useful if you're certain the engine is original.

 

yes but using the year as a reference if it was made that year more than likely its stock if it was never on there then of course its been changed. more than likely its stock though.