Help: LBZ cp3 on LB7 truck

[sddmax]

I am in the process of swapping my lb7 pump out for an lbz. I have everything swapped over to the lbz pump but ran onto a problem with the top fuel port size. The lb7 has two fuel fittings sticking up on the driver side and the lbz has the back one plugged, when i went to put the lb7 fitting in there it was too small??? Is there a special part i can get for this? I have a pull this weekend so i'm really trying to get this done. Anyone know what to do?

 

[sweetdiesel]

Im obviously not understanding what your saying they are all the same size inlets and outlets i direct swapped a lb7 to a lbz and didnt change anything

 

[juddski88]

x2

 

[streetwise]

x3

 

[sddmax]

Thanks for the help Simon! Sounds like a strange deal to me. I really cant believe both lb7 motors and cp3 pumps are different.

 

[sddmax]

I will try and get pictures up of the different sizes tomorrow. Also i will get pictures up of the different sized gear pump shaft.

 

[sweetdiesel]

I talked with Casey on the phone tnight and seems he may have a oddball motor
I know GM pumped out around 600 of these motors that whre complete odd balls

his return fitting measures close to a 5/8s id I know i could help him if i lived closer but i gave him some suggestions and hopefully he is pullin by friday night

 

[JoshH]

I talked with Casey on the phone tnight and seems he may have a oddball motor
I know GM pumped out around 600 of these motors that whre complete odd balls

his return fitting measures close to a 5/8s id I know i could help him if i lived closer but i gave him some suggestions and hopefully he is pullin by friday night

WTF? Why is that? Where were these motors used?

 

[sweetdiesel]

WTF? Why is that? Where were these motors used?

I was stumped also but i do remember there where around 600 motors released that had odd cp3s injectors and heads


Ill make ageuss that he got one...only explanation

 

[juddski88]

like the preproduction one Vinny bought?

 

[TheBac]

Maybe use one of those PPE fittings to fix it, or are the CP3 threads themselves the wrong size?

 

[sddmax]

Maybe use one of those PPE fittings to fix it, or are the CP3 threads themselves the wrong size?

The cp3 threads are the wrong size(bigger), but i ended up getting a II dual feed line fitting machined to fit perfectly :thumb: Thanks for all the help simon! I am still confused as to why the cp3 was set up like that Just seems strange. But i got it all working now and were working on the tuning now for tomorrow and Saturdays pull

 

[juddski88]

damn...i have those fittings here that i needed to get rid of, lol.

 

[crash85]

how much more does a lbz cp3 flow than a lb7? is it worth the swap because I have an lbz motor on an engine stand I pulled out of a truck

 

[jonathancasey19]

how much more does a lbz cp3 flow than a lb7? is it worth the swap because I have an lbz motor on an engine stand I pulled out of a truck

x2 I'd like to know this as well.