Boreen

Today I did the first run after my LS3 swap finally.
Over a year ago now I pulled out my built up 355 SBC that wasn't exactly thr slowest car on the street. Had it paired up with a 700R4 that was weak.
Pulled the SBC, 700R4, driveshaft and diff out and sold it all.
Replaced the engine with an LS3 pull out from a 2010 Vette. Came as a long block only tho so needed almost everything. Got the factory intake, throttle body, 2010 camaro from accessories, gmpp LS376/525 controller kit. Went with an LS7 clutch and flywheel, and a T56 from a 2002 Camaro. Also went with a rear diff and aluminum driveshaft from a 2002 Trans Am WS6. Went with hawks 1 3/4 headers with 3" collectors and have an SLP loudmouth 1 exhaust that needs to go on still. When the engine was on the stand we went through it completely. Arp head bolts, new timing set, little bit of head work, new valve springs and a big cam.
While I was building it I also replaced every bushing on the car, Spohn LCA's, BMR strut tower brace and LCA relocation brackets. New rotors, calipers and pads om the rear diff along with a TA performance diff cover. New calipers and pads on the front until I do willwood brakes or something. Sportlines also gave it a nicer height but the car is a little nose light still. Might go with coil overs over winter.

Took it for the first drive today after a year and a bit. It's open headers right now so its definitely running rich and I'm just using the base tune on the GMPP computer. But all I can say is wow! I am impressed for now.
We have two other quick cars, but they are both autos and this thing is definitely the fastest in the yard.
I am really hoping that the slp loudmouth will quieten it down a little tho.
I am sure my rear end is gonna be my weak point now unfortunately.
One thing I don't like tho is that it has 3:42 gears in the diff. At 70mph I am revimg about 1500-1750 rpm (pending how much my tach is out) which might get me good fuel economy on the highway. But it bogs the engine down slightly at that rpm with the cam that's in it. Would 4:10's be that much better for me? I would like to one day throw a set of slicks or street slicks on the car and try it to see what it can do at the track. So I'm sure a new stringer rear diff is In my future as well.

Big thanks to this forum btw! I came on here a few times looking at other swaps to help me if I needed. It wasn't too much, but still there for me.

It was alot of long days, longer nights, countless headaches and dollars spent. But that first test run made it all worth it.

cosmick

Congrats!
Yes, try gears now before ordering a 12-bolt, 9", or S-60. 3.73:1 and 4.10:1 gears can both be found in salvage yards, much less cost than the cheapest new sets, try 2.2L S-10s with automatics for 4.10:1 gears that will bolt right in. And check the backlash before you pull them. That will help with setting them up in your axle so they will run quieter.

UnstableAviator

Bypass the 4.10's when you go aftermarket and go for the 4.30's. The way your LS3 will rev and carry power to 6500+rpm makes the deep gears very effective and a blast to drive.

Glad you enjoyed the first drive, it just gets better from there. And yeah...it'll be just a little quicker than a build 355.

cam-

Congrats!!!! Happy to hear

86White_T/A305

The first drives make all the headaches and money spent just a thing of the past and worth the wait.Gets some pics/vids for us all the share the moment with you lol.

Oh and give it some time for the front springs to settle,the rears are softer spring rate i believe on the sportlines but the fronts took awhile before it leveled out for me.I also didnt put the front rubber isolator in the front just to lower the car a bit more.

AutoRoc

iTrader: (1)

Nice overhaul! Big power, big weight reduction. The SLP is a loud exhaust but a bit quieter than true duals with race mufflers. Open headers are rediculous haha

Boreen

Thanks guys!!
Yes the first test run definitely made it all worth it. I am hoping by the weekend to have it on the road with full exhaust.
I need a new high pressure power steering line now as well (sprung a leak). Anyone know what lines will screw into the factory 91 box? I'll be chopping off the fitting at the pump and putting my own on anyhow.

Really good advice on the gears guys! Didn't know an S10 would have 4:10's from factory. I am thinking with 4:10's or so I will be able to pull 6th alot nicer. It kinda bogs slightly in 6th because its such low rpm with this cam.

I will get you guys some videos once I find my GoPro, and I will definitely post some pictures soon.

Boreen

Got the exhaust done the other day at the exhaust shop. It's not much quieter than open headers, but the sound is out the back now.
Drove it around for a while and couldn't keep the smile off my face everytime I gave it some throttle.
All was well until I was in the town over (30km), went to leave. Grabbed third on the highway and it made a pop sound. Now there is a popping or something similer coming from cylinder 1 or 3. I shut it down instantly and got a buddy to bring my truck and trailer out.
Anyone have an idea what it could be? I don't wanna run it at all. It almost sounds like its backfiring through the intake but I can't feel the sound in my metal intake with my hand at all.
Tore the valve cover and all the rockers out on that side expecting a bent pushrod or broken valve spring, and everything looked good still in the valve train. So now I'm scared and wondering what I did.

Flip 2

iTrader: (1)

Any luck with this?

cosmick

Maybe too late in this case, but GM 7.625" axles came with 4.30:1 and 4.56:1 gears in some Isuzu P'ups. If you want to know what to look for at the used parts yards, you'll have to research years/engines/etc for yourself. But it would be a cheap way to try such ratios.

Boreen

Ended up being one broken and one bent pushrod on cylinder 8. Fixed it all up the other day and runs mint again.
Thanks for the into on the gear ratios, gonna have to try something different as I lose speed in 6th.

Atilla the Fun

That's how it's supposed to be. ALL T56 cars have top speed in 5th gear. If you run enough axle to get around that you'll render first gear useless. The only exception is if you get some really wrong gearing changes from Rockland standard gear. In any case, any combined ratio that will give top speed is more than you need for best MPG. Taking your statement the other way, rectangular-port heads give up far too much torque below 1500 RPM, and so do healthy cams. combining them may well result in lugging, even with custom tuning, until you change something. With a stock LS3 cam, you should be able to drive your current gearing with no issues. If you try a cam that won't, then it's too aggressive.

Boreen

Thanks for the info. I guess 6th is basically a double overdrive with these Trans? 1-5 pulls hard and I love it. Still would like more tho.
The cam is slightly aggressive, nothing too huge (low .600's lift I believe). So that does affect some drivability.
I think I might need to run a real muffler eventually. Right now I am running hawks 1 3/4 long tubes with the hawks y-pipe to 3" SLP loud mouth one exhaust. I don't think it's much quieter than open headers anymore.

Also. I'm not running a PVC system. I was told to run a line from my cold air intake tube to the passenger side valve cover vent and cap off the vent on the drivers side valve cover at the back. Can anyone confirm this for me? I hate that it kinda smells like oil fumes around the car.

Hopefully over winter here I am going to get it tuned better, get some gauges that all work and are accurate and start my saving for a supercharger now (never enough power)