I figured that I could sneek BudHayes, Mangeled, and/or BlackGMC and all the other regulars in here with that title ...


Here's the plan guys, I've been rocking the search button so much it's probably worn out, lol.

I grabbed a set of Milled 243 heads with the yellow springs, combustion chambers are ~59, I'm planning on running .030 head gaskets, I think this'll run my compression somewhere in the neighborhood of 9.9-10... I think. Planning on making the E-fan swap, and LT's with full exhaust.... Now my delima

I'm hung up on my cam choice, either the XR269HR or its little brother the XR265HR... I'm not planning on changing converters, I do some light towing. Main question.. will I gain enough with the exhaust, heads, CR boost, and E-fans on the low end to make up for the loss of going with the 269, or should I just go with the 265, which according to the dyno sheet that I saw and what everyone has said, with the 265 there's no loss on the low, and really wakes up on the high side.

I'm leaning towards the 269, but a couple threads I left they said that the low got a little squishy, just looking for some guidance, I'm planning on doing everything at once once tax time rolls around.

 

I am very happy with my xr265hr lowlift!
I am curious what a bump in compression and alil better flow would do for me!

 

Actually, you posting in a thread I started about 3 months ago is what made me start looking it it.

 

i went back and read the other thread you made.
I think you be happy with a xr265lowlift.
Mine drives like stock but with way more power,no real noticeable drop in fuel mileage.
I drove mine on the stock stall for a few weeks that was no issue,did great!
The lowend power is fun and the cam pulls hard to 6400..no dead spots in powerband hard pull all the way!
No matter where you stomp it at it will pull strong!

 

I had the XR265HR 212-218 in my 04 5.3.

Absolutley loved it, sounded awesome. The truck had a STS turbo in also and a 2800 PI stall so im sorry its not identicle to your combo,

But i can tell ya it it made a big difference in how my truck ran, and i could still use the truck as a truck, i could tow, and have fun. It felt stronger all over.

You dont want to sacrifice ANY low end in our heavy trucks!

 

Is that 265 cam a simple swap or do you have to do lifters and stuff in a 5.3

 

same swap...no lifters needed. pushrods and springs however

 

You need a spring upgrade, the lift on the cam is is more than the stock springs will handle. I read a thread where someone was concerned about seat pressure of the yellow springs, but there are people running both the 265 and the 269 on yellows without a problem. I think with any cam upgrade from stock everyone is going to recommend hardened pushrods, for no more than what they cost, it's better safe than sorry for sure.

 

That's generally what everyone has been saying about it, and it's looking more and more like that's the way I'm going to go, I was just thinking that I could squeeze a little more out of the top end with the 269 if I was going to make up for my loss of low end with my other mods.

INFO : I ran the numbers through Comp's CamQuest6, running custom flow numbers for the 243 heads from smokemup.com, it recommends the 269 as number 1, interestingly enough, the 265 is the second one in the list, and has a higher est. average HP and torque number, can't tell you how accurate it is, just found it interesting.

 

i run my 265 on LS6 yellow springs with no issues...rev to 6400
i am still on stock pushrods too!