TravisH

iTrader: (1)

Thinking about molesting my motor this winter and I'm just curious what you guys think the weakest points are. I'm planning on doing a cam, springs and pushrods, but are there any other parts I should worry about when turning higher RPM's right now I'm at 6000 and I probably wont go past 6500. Also, What is involved in a cam swap other than just a cam, springs, and pushrods?
The motor has 121500 on it now and the only noise it makes it a slight ticking from a lifter.

99Silver6.0

iTrader: (1)

Rods and rod bolts IMO are a point of needed attention. They are powdered metal but..... They could be a nice pretty Manley H-Beam or something worthy. Pushrods also gotta go. They are weak, thin, light pieces of crap. Timing chain should be dealt with too. LS2 or any double roller is cool. Springs will have to be changed too unless you want valve float at high RPM's. If you intend to rev it high and hard you might as well go with titanium retainers. Do whatever possible to lighten up the happy end of that valve spring. Cam swaps are easy. Motor does not have to be pulled, valley cover stays on, heads stay on, intake stays on. All you really do is take everything off the front of the motor. A/C condensor stays in and the radiator comes out. YOou can pull the cam out of the block with about a fingers width of room left between the condensor and cam. But none-theless it is easy to do. Just a bit time consuming.

02sierraz71_5.3

iTrader: (2)

with that mileage on it and lifter problems I definately wouldnt be running it hard in the 6400+ range. Honestly I wouldnt even invest money in it I would buy a cheap 6.0, do cam/heads maybe some arp hardware if you plan on 6700+ rpms the stock bottom end on these motors seems to be extremely solid and can take tons of abuse. If memory serves me there are several guys on here that turn em up as high as 7k and havent had any problems with the bottom. I think parish made crazy power on a stock bottom end with not complaints. Pushrods, light weight valve train, Id go with an adjustable jezel rocker arm setup if your worried about valve float.

I dont think the 5.3 is worth the expense of upgrading major components it just wont make good power without an adder, youd be lucky to get 320 at the wheels. The 6.0 on the other hand Id be shooting for 450 at the wheels NA.

my .02

99Silver6.0

iTrader: (1)

There is that too.

gonzo 6.2

iTrader: (8)

who here has seen a failed stock rod bolt?

budhayes3

iTrader: (19)

With 121k, if I was ganna do that much work I'd replace the oil pump too, since you already have it that far apart. Go for a nice ported LS6 pump.

storm5.3

iTrader: (1)

Well I guess I'll speak up on this one since I didn't start modding until I hit 125,000 and now have a little over 193,000 on it. I would get at bare minimum and the first thing a new set of lifters if going w/ anything over .530 lift. A Ls6 ported oil pump, new springs Comp 918 or equvilent, hardened pushrods, and whatever camshaft you like after those bare minimum supporting mods. Now my motor will probally fall apart the next time I turn the key after saying this but all I have is 918's, hardened pushrods and a cam. All other internal engine parts are stock and I usually hit my 6600 RPM shiftpoint at least twice daily and at the track I've hit my 7000 RPM rev limiter a few times and so far she's holding together. The only thing I do have problems w/ is a lifter that starts to tick after a few miles of driving when the engine is cold ( lifter won't pump up, hence I suggested new lifters...) and after approx. three miles of driving it pumps up and stops. That's about it and this is w/ an engine that has almost 200K on the clock...JMHO

Bad_Apple

iTrader: (1)

I would get good set of pistons, and cam. Than replace the spring, pushrods, and rockers.

chevyerett

iTrader: (1)

Call me crazy, I don't care. My engine has about 170K on it, and I just put the cam in. I also put new lifters, new timing chain & spockets, new oil pump (all GM oil pumps are the same, LS6 or whatever, they are the same, besides the old body styles), and of course the new cam, springs, and pushrods. I also put some ARP rod bolts in too. Also some new injectors out of an 8.1L

*Knock on Wood* It's been driving good so far.

If you do replace the oil pump, get a NEW o-ring. Save yourself the misery I went through. The guy at the dealership said these style oil pumps are practically bomb proof anyway though. He said the commercial airplanes use the same design.

O3GMC

I've been around here (truck section) for a while now and I've never seen anyone post about a broken timing chain, connecting rod or rod bolt....maybe I'm wrong. I've seen valvetrain problems and broken pistons....but its always seemed like these blocks can take as much as you can throw at it (within reason) as long as the tune is good.