Carb spacer on stock 454

[USSkoval]

My '79 K30 Crew Cab dually has what I believe to be a stock 80's 454 under the hood. I do know it is a 454 though. It has the stock cast iron low-rise intake on it with an Edelbrock carb.

I'm not wanting to change the intake at this point in time, I'll save that for when I do a cam swap. In the mean time, would there be a noticeable benefit to running a carb spacer? If so, how thick?

[prostreetC-10]

Does it already have some kind of an adapter? Ed's are square bore and your stock intake should be a spread bore pattern. A 4 spacer can help that kind of an intake because of the short runners. "Noticeable" might be a tough one to answer though. Go with a simple black 1" spacer but make sure it's a 4 hole.

[USSkoval]

Yeah, IIRC, there's a short spread/square adapter on it already. Maybe 5/8 inch thick?

[USSkoval]

I think I also need to replace the carb. It's only a 500 cfm.

[prostreetC-10]

What is the number on the lower left mounting flange of the carb? There are far more 600's thank 500's. Until you do your cam and intake swap, I wouldn't even mess with the carb. A 500 will feed a stock 454 just fine anyway.

[USSkoval]

It's a 500, I checked the number when I bought the truck. I'm also just assuming the motor is stock (it does have headers though). It has been rebuilt recently, but all I know for sure is the block number and it has the later style accessory brackets on it. I haven't pulled the valve covers to check the head numbers.

[Youngbuck7072]

IMHO, get a bigger carb man, i run a 650 on my bone stock 350, and it gives it enough juice w/o flooding it

[USSkoval]

It just matters how it's tuned. I run a Holley 750 vac secondary on a little 327, it's worked fine for years. Best carb I've ever had.

This 454 seems OK with the 500. Throttle response is excellent. Oddly though, it tends to load up a bit if the truck idles for more than a minute or two. I haven't messed with it yet though.

[prostreetC-10]

Throttle response is excellent because of the small venturies. If it's loading up at idle, you have something going on with the idle circuit.

The 454's on the last 70's usually were smogged to dead, had no compression and don't need very much cfm at all to run at max. We also have to remember that this is in a C-30 which has just a little bit of rolling mass. Go through your carb if you want or leave it alone but I still wouldn't mess with another carb until you figure out what direction the motor is going. When it's all said and done....you probably won't wind up with any combo that will need more than 600 cfm.

I built a little 600 for a local guy here and decided to try it on my car hauler before I put it on his truck. It was pretty amazing how it delivered almost no changes over the 3310 I run on the truck now. It flat ripped and this truck breathes really well. Early heads, really open exhuast and a fairly big cam for a tower.

[USSkoval]

The motor will stay mild. Low and mid range is most important to me, even if it wasn't a big heavy 4x4. It is nice that the truck is 4.56 geared though. I just plan on a mild hydraulic roller, a good intake, and a Holley. If I end up having the time, I may install the TBI setup I have instead.

[prostreetC-10]

A little 600 vac carb would be a great choice and a 670 street avenger just might be a perfect choice!! Just make sure you wind up with a vacuum secondary carb.

Man.....4.56 is deep. Do you get passed by kids on skateboards??

[USSkoval]

It has 35 inch tires on it, it's a really nice combo for power and economy (still not much economy though, lol).

I actually have a 670 Street Avenger not in use right now, but it's kinda fubared. Some idiot tried to "fix it". It basically needs completely rebuilt now.