Hey everyone. I'm new to the LS world (mainly SBC's and vintage engines) and I just got a good deal on a 05 5.3L from a guy who was doing a Cummins swap in his Silverado just down the street. My friends all have LS powered vehicles of all different types so I figured I'd join in. The only difference, they are all EFI and I want to go carbed.

The car it's going in is a 1956 Austin A50 and will be a street strip style car. Kinda gasser in looks. Shooting for no more then 2500lbs in weight.

Since the car is so light I don't need a TON of power but something to give me a fun respectable ET.

So far the drivetrain parts I've collected will be major overkill (but maybe perfect for the future). A narrowed 9" with ladder bars and coil overs, Unselected gearing (which I need your opinions) and a choice between 2 transmissions, a stock rebuilt th400 with a 3500 stall, or a 4l80E which I'd like to run the trans-go-3 full manual kit with vac modulator and no decision on a torque converter.

I'm leaning towards the 4L80 because I want to be able to drive this car on the highway and I like the idea of OD and a lock up converter. Plus I can choose more of an ideal race gear instead of a compromise with the th400 making more street friendly.

So anyway I'm looking to leave the bottom end of the 5.3 stock and the heads. The heads might get a port job in the future but right now I just want to get it running and driving.

What intake would you recommend? RPM or Vic Jr?
What cam would you recommend for a stockish carbed 5.3? maybe something that may accommodate future ported heads.

I already have a Holley 650DP that I can use or would you recommend something different. I don't think I'll be revving the snot out of this thing with the stock heads and rod bolts so I'm just guess 650cfm would be enough but maybe I'm wrong.

I'll just leave you with those Q's for now, maybe you need more info from me to help me answer them.

Any help is appreciated, Thanks!

here's the car/engine/final design







Lot's of work ahead of me this winter!

 

There is a link to a very interesting article on here where a guy built up a 5.3 truck motor with the two intakes you are considering. With the stock cam and valve springs the thing totally ran out of breath at a fairly low RPM. As a result the dual plane was clearly the better choice.

Having said that, a car that light will have issues using a lot of low RPM power depending on how much tire you end up with. So I would say pick the intake when you figure out what type of cam you are going to end up with. Valve float with the stock springs will limit your RPM before the rod bolts do. In the mean time hopefully someone will post a link to that article I mentioned.

For the stock 5.3 it is safe to say most guys will recommend the 650 carb. Overdrive is worth every penny IMO. I wouldn't build a street car without it. You should easily pull down 28 mpg with a stock, carb'd 5.3 and decent gearing.

Cool car by the way.

 

Thanks!

I would also be upgrading the valve springs. I believe i've seen similar test to what you've described.

My tires will be between 28-29" tall. Gearing I haven't calculated yet, stall I'm guessing around 3500. I'm starting to lean towards a Vic Jr for the intake as I don't believe I'll need a lot of bottom end torque to get this car moving. Basically I just want to find a cam that will max out the stock heads with better valve springs and maybe even be a little bit to much so in the future the cam will respond well to head porting. Also want the car to sound mean as hell... I'll be making my own headers that will be fenderwell exit wide open for the track and block off caps to a full exhaust.

It would be awesome if an off the shelf cam would work because I may be able to come across one used as opposed to a new custom grind or something. My friend has a MS3 in his basement but I think it's too much cam with the wrong LSA for my application.

 

Here are some car update pics.
























The rear wheels are just for a visual mockup. Actual rears will be 15x10's with a slick or a DR sticking out about 2" from the sides of the car.

 

In my opinion, a car like you have described should have a cam with a hotrod type idle. You may have a look at the Comp Cams Thumpr cam series. The smallest Thumpr LS cam will have a roudy sounding idle, good midrange power and a design that will not be too hard on the valve train components. It will work good with either the Performer RPM or the Victor Jr..

For the choice of intake manifold, I would base that choice on your torque converter stall RPM. 3500 and higher, I would choose the Victor Jr. on a 5.3 liter engine. 3500 or lower, I would choose the Performer RPM. However, if there is a chance you will later get the bug to go racing with big heads, big cam and\or nitrous, choose the Victor Jr..

 

Unless you are Planning on 500+ hp then you should consider a 4l60e bc a 4l80e will eat up a lot of power and is heavy as hell...I got 80k miles on my 4l60e making about 450 crank hp and it has never missed a beat...just a thought cool project though

 

Thanks, i just was leaning towards a 4L80 because of the gear ratios. I'm not a fan of the 700r4/4L60 first gear ratio.

 

4l80 will hold 600 stock. Major upside. If allot of abuse will happen I am against a 60 as well.

 

Thanks for the cam suggestion, ill look into those, and if they sound mean that's an added bonus. I think I'm going for the vic jr. There will probably be more engine modding in the future, I can't deny that lol.

Ya that's what I like about the 4L80, if I can find a good deal on a low mileage one and convert it to full manual with the trans-go-3 reprograming kit with the vacc modulator, the biggest cost will be a torque converter and I won't have to worry about the trans for a long time.

 

Is there any specific year of 4L80 I should look out for? the deal I had on the other one may be falling through....

 

Any will work I'm sure, but the newer ones are probably best, 99 up. Perfect bolt together, as well as converter alignment.

 

Thanks! that's what I figured.

I've got a Vic Jr. and an MSD 6010 on it's way! very excited.

Another question, since this will be a street/strip car and auto, do you recommend a vac secondary carb? I'll likely i'll be using a Holley, I also want a choke.

thanks!

 

If you are using a high stall converter (over 2500 RPM), do not use a vacuum secondary carburetor. A mechanical secondary carb is what you want. If you want a choke, you can choose a model 4779 Holley 750 CFM.

 

If you ordered an MSD 6010, you may have ordered the wrong box. That motor, being an 05, may have the 58X reluctor. If it does, you have to use the 6012 box. Look at the crank sensor to see what color it is. If it's gray, you need the 6012. If it's black, you need the 6010.

 

I have an 05 5.3 and it's 24x reluctor, but check to make sure!

 

It's most definitely black.

 

It's coming together! Still having trouble choosing a cam, the thumpr cams are quite tempting tho for an out of the box cam. The carb is just a mockup 650DP. I plan on going with either a standard Holley 750DP or the HP aluminum version.

Stock manifolds are not staying either, just wanted something on there to make the engine look pretty on the stand.

PS I have to somehow make my vintage corvette valve covers workout!

 

check out speedway motors for their valve cover adapters for ls1....thats what im using..

 

thanks for the pics, I saw those on their website. I tried looking up installed pics and couldn't find anything. I was worried that they would space the valve cover up too much but that looks great! I will definitely consider those if I don't end up making something of my own.

 

Any updates on this?