why when I look up the gm part # for the lt4 intake I come up with 2 different numbers which is right 12550630 , 12550631.also which one is better the gm lt4 intake or the lt4 from edelbrock, thank you.

 

The LT4 intake is internally the same as an LT1 intake. Why are you looking for one?

The Edelbrock stuff is a joke ONLY thing it has going for it is it is still available and the GM LT4 intake is discontinued.

 

looking at a lt4 motor with no intake

 

631 is the casting number and 630 is the part number to order one if you still could.

BTW, 96caprice is some what correct. Internaly they are the same up to the runners. The runners are not the same. The ports are higher on the LT4... That being said you can easily convert an LT1 into an LT4 manifoldwith some welding.

 

The actual ports are the same on the LT1 and the LT4 intakes. Yes, the head ports are taller on the LT4 heads, but not on the intake. The LT4 intake ports are mismatched to the LT4 heads, since they are basically the same at the LT1 intake ports. The LT 4 intake just has more meat on top of the runners, to allow them to be ported to match the LT4 heads, but from the factory, they don't match.

 

thanks for the info

 

Just to make sure your clear on this. You can not get a new LT4 intake from Chevrolet. The only new ones available are from Edelbrook.

 

Another clarification, most people claim the ports are raised in the LT4 stuff, this is NOT the case, the head ports are taller and much larger but the floor is in the same place.

Honestly you should do more research and maybe pass on the LT4. Block is a LT1 4 bolt block BUT if you need 4 bolts you should be using aftermarket caps anyway be they straight like that block or splayed, plenty of machining still needed if putting aftermarket caps on a factory 4-bolt block so it is not some wonderful thing worth paying a lot for.

The heads while in bench racing are great results in normal street/strip or even many all out race vehicles don't really back that up.

The crank is nice BUT if you get it turned undersized you grind away what makes it stronger.

The rods are a big hassle to rebuild if you can find someone willing, the fractured cap thing is nice till you need to resize, then you need to find oversized bearings, as in oversized on the outside, not a normal thing but are available.

If it is CHEAP then consider it but certainly do not pay a premium for it as none of the parts are all that wonderful.

 

thanks for all info the motor was junk not what he said it was