HP vs non HP engines

[sleepychallenger]

can anyone tell me what the difference between the HP and non HP motors were. i found some 383 non hp motors, just wondering what they are worth and if i should pick some up?   

[73Chally]

I thought I had read somewhere that there really was no difference in the blocks themselves, but I'm not positive if what I read was correct.

[bb71challenger]

HP motors usually had a windage tray, different valve springs, cam, compression, and exhaust manifolds. The blocks are exactly the same so for most us who are going to build a motor anyway it really does not make much difference whether we get an HP or non HP core. For those who are trying to date match an engine it is usually a little more critical that they get the right kind of motor for a non numbers car. I have a 68 HP but since I am going to build it anyway it would not matter to me if it was HP or not.

[Chryco Psycho]

 

[sleepychallenger]

thanks guys. i thought that was what it was but i also thought that the heads were different. thanks a mil.

[Moparal]

The only significant thing I have ever found in the block castings of HP engines is that when I checked the 10.72 block deck hieght. it was closer to specs for higher compression true ratios.

An easier example would be to take a crank rod and piston and check piston height  in a non hp engine, then take and check it in an hp engine block and for the most part, the piston will be closer to the deck. 

But when you deck the surface and square it all up, it all becomes equal. I have done this many times. I usually put the center line at 10.7100.  It's time consuming, but the final results make the outcome much better

[sleepychallenger]

Thanks Alan, I am really considering buying another two 383's. one to build for performance and another stock (hp specs). Just incase mine decides to go out. i wont get rid of it due to the numbers matching, but until i am ready to sell it, what is the point of putting more miles on the numbers motor???

[70Cuda]

Here is a good link someone passed along to me that helps clear things up: http://www.440source.com/blockinfo.htm

I have my numbers motor sitting around for my 71 383 R/T all rebuilt and mostly stock ready to go back in the car but I won't be racing or pounding on it (that much) but not everybody can afford to have multiple motors rebuilt / sitting around.  I'd put it back in but the built up 440 I have in it right now is just too much fun to pull out.  It just depends on what you want to do and what you can afford.  I have had other guys tell me they'd like to pull the numbers motor out and do the same - my situation wasn't intentional, just the way the car came.

[moper]

there is no difference in most things, except the windage tray and oil pan setups, and the cam choice. The "extra sompression" is a myth, as is the thought hat any factory machined blocks were close to blueprint spec. Not even Hemis got that kind of extra attention. If the decks were flat, they were fine. Most are between .030-.050 taller than the blueprint spec. Which is where the compression loss comes from. that HP stamp is for the assembly ID, and things like carbs, distributors, and exh manifolding were also different. So the assemblies carried the HP monicker.