2K Silvy

Now would your mind change IF I planned on a future supercharger? It isn't a guarantee but if would be nice. That is kind of why I was leaning more to the new pistons and such. I don't know if the stock ones are so great. Also the gains by getting new pistons would be cool. I am sure I would be getting close to 2k though.

Another question would be would the piston slap go away with new rings? I thought it was just the bad material of the pistons that expand. That drives me absolutely insane every time I start the car (Here in Michigan) and it just knocks and knocks.

I like the idea of the 5.3 crank weather it be a new engine or mine and the bored out pistons. I can get a 5.7 out of them and if what I read is true still be able to throw a super on there and be safe.

Camin00

With $1500 your going to rebuild the short block how you want, but no cam upgrades

average $1000 for cam swap and parts to go along with it, springs, lifters, push rod, timing chain you get the idea

with your budget wouldnt deal with the heads other than milling them for more compression should be around a $100 for .01 to .03 shaved

Big ports and high air flow in small cubes hurts lowend tq. The truck heads and intake keep the air flow velocity high in order to create more tq. Big port heads would definitely help out top but that is not what your going for. Which is good b/c you can save money by reusing the stock heads The appropriate cam is designed to flow with the stock truck heads to create more tq from the cam.

If you want true lowend torquer truck that is DD get the compression up to 10.1-11.1 if your going to run 93 octane with a good tune

vinci 210/218 .551/.551 on 116

or comps 212/218 .

perfect choices for lowend tq and all over power band gains

A set of headers

On stock wheels and 5.3L size motor with listed upgrades easy 330-340 rwhp 340-360 rwtq possibly more with high compression and premium tune

2K Silvy

Alright is it okay to use the stock heads if I bore to say 3.898"? Wouldn't the engine kinda starve for air with the bigger bore and need the bigger heads? Would it match up with the head and the larger bore?

Also would the long tube headers add some power? Are they louder than say the short tube ones? Any clues on what kind of power you could possibly get out of the upgrade?

Is there anyone who has got into the 11:1 compression ratio on premium? I just want to make sure its something feesable before I go ahead and invest in parts.

2K Silvy

So the mind has decided what I am doing..

I am getting the 5.3 crank. It has bearings and is good to go.
I am getting the 5.3 rods (anyone has a set for cheap lmk)
I am using 4.8 pistons..some of them high quality engine tech (speedpro or whatever) pistons. Long as they work and don't knock I am content.

As for the upper end I am going with stock heads hopefully shaved down and bump up the compression ratio.


My question is with stock flat tops how car can you shave the head before you would have issues with valve clearance? Any ideas anybody?

Camin00

The ls1 heads have the same size ports as the truck heads but larger valves for slightly better flow


If you
Run flat top pistons

Mill the heads .03/thirty thousandths (Do not have the heads milled more than this)

Run .04 thick head gaskets you will be just shy of 11:1 compression 10.976:1 to be exact

While the heads are off put a set of ls6 springs on $70. yellow good to .550

With the heads being shaved so much you will need a pushrod checker to get the correct length push rod my guess would be around 7.325 buttttt I have no idea b/c every motor is different

as long as you do not exceed .550 lift you will be fine < Do more research on this

run a small cam for tq and stock stall

Camin00

Ls7 come stock with 11:1 compression and are tuned for minimum 91 octane. With a custom premium tune on the ls7 easy 20-30 more rwhp

So to answer your question yes you will be fine with 11:1 compression and a good personal custom premium tune

Do not get a mail order tune

A custom "driving" tune is better than a dyno tune in my opinion #s are one thing but how it actually drives and shifts those 3#s is what really matters

Camin00

Forgot to mention

A lot of budget ls1 guys throw a set of truck heads on when they do the cam swap. Cheap way to bump compression up

I recommend making map charts of the route you could do for you build. In the charts list the money for them and the hp gains that come along

example if you had $500 only you could choose a set of 243s which would gain you 10-15 rwhp or you could get a set of long tubes for 300-500 depending on finish that would gain you 20-25 rwhp

shorty headers average 10-15 rwhp longtubes average 20-25 rwhp. Long tubes are slightly louder than shorties but if you get a quite muffler they would be almost identical in sound. Most people and I will tell you longtubes all the way

I had shorties originally and switched to longtubes wishing I had never wasted my money on shorties, but live and learn

My longtubes gained 14 more rwhp and 9 rwtq over the shorty headers

If you run a y pipe with the longtubes go 3" exhaust, if you go true duals go 2.25 or 2.5. With the small bore we loose some lowend power by running ture dual 3"

2K Silvy

First thanks for your time, I appreciate the help.

I am indeed going to do the flat top pistons. The might be stock 4.8 depending on the condition of them or not if I have to hone/bore. I am going to rip apart the engine in the next few weeks so I will see. Though I might upgrade just to get rid of slap on cold starts. It can't be good for the engine.

Right now it is undecided on the heads. I am "leaning" to the stock ones but shaved to get me close to my goal of 11:1. However I know the 243s might be better in the long run, especially if I ever am able to add a supercharger or something. Of course I can just upgrade later though. Do you think it is worth the I am going to shoot 500 for the heads? I just can't see it being THAT much more power. I think a new intake/throttle body would be a better investment. Then I already got stockers so I can shave them and even attempt a Mikes custom port job too haha. It is cheap and it should work..maybe.

I found a set of long tubes so I will deal with the added noise. It just makes more sense to do it right. I am thinking a custom y pipe to get rid of the cats and rear o2 sensors then turn them off in the tune. Keep it a single and split into a dual at the muffler. I was also thinking about one of them cutouts before the muffler and running it into the back pipes using y pipes. I could have a second for the cutout muffler next to the other one to give a nice tone to it.

It's all ideas right now but I think I will go ahead and do that, make a map chart. I have a giant list but its harder to visualize.

Camin00

Boost likes lower compression around 9-9.5 range

So If you ever get a supercharger get a set of 317 6.0 truck heads they flow the same 243s and would lower your compression around 9.2 with stock height gaskets

I dont know much about piston slap so I would start a new thread asking about it and how to fix it

message me when you figure out what your doing. Nobody ever shows me after I help them haha

Camin00

oh I just posted a thread asking about the tbss intake

with truck heads it will hurt power

with 243s or ported heads it will give 10-15rwhp

Remember if you want tq big ports is not the way to go, a small cam give tq
DD fun ^

If you want a top end screamer go big ports and large cam but then a stall is needed and mpgs go to ****
Race toy ^