I've got a 5.3 shortblock that I was going to swap the crank and connecting rods from into my 5.7 block. Right now money is getting tight and I honestly just want this thing to run so I'm considering putting my LS1 cam in it along with a set of fully ported 706 castings that came off of the 5.3 shortblock and some 28# injectors. I'd like it to at least be comparable to the 305 hp factory rating, would the 5.3 make anythig better than the 285 it's rated from the factory with the cam and ported heads?

 

To clarify, the LS1 cam I'm putting in is from my 99 LS1 and the specs are different than the later cam which was closer to the stock LM7 grind. The specs on the older cam that I'll be utilizing are as follows:

202/210 int/exh @ 0.05" duration
0.496" / 0.496" int/exh lift
116 LSA

 

not much better than a stock 5.3 cam. you can usually find a good cam on ebay or here for a cheap price.

 

Yes, but I'm not wanting to spend anymore money on parts. I already have a cam and a lot more parts that I was going to use once I swapped the 5.3 rotating assembly (with LS1 pistons swapped on) into my LS1 and have a nice build but I'm just running low on cash. I've only got one more year of college left, I have a wife and two kids and I'm just starting to lose interest in this project with the way I was wanting to do it. I want it to run so I can enjoy it and keep the LS1 block for a future build once I'm finished with school and have a real job so that's why I toyed with the idea of swapping the stock LS1 cam and the ported 5.3 heads back onto the LM7 shortblock. My main concern is losing power, it'd be nice to keep the power around the 305 factory rating and I was just wondering if the cam and ported heads would at least put me around that.

 

A ls1 cam in a 5.3 will net you next to 0.. A decent upgrade is a ls6 cam, that still isn't gona get you a bunch of hp but def more then a ls1 cam.... Look around save your money and get a decent cam you want the first time.. It is too much of a PITA to be swaping cams out. Cause i will bet you will def not be happy with a ls1 cam...

 

Plus look at the expense to get it running with your LS1 cam, and then blow it apart again to swap cams. Then look at what your time is worth being a college student with 2 kids. I have 2 kids and 2 project cars completely torn apart....to me, my time is so valueable I only want to do it once. Granted I could throw it together and redo it later but if you don't have time to do it right the first when will you find time to redo it? Trust me, wait and try and find a cam cheap enough to use.