348 chevy

Hey Hambers. Does someone out there know what dual quad intake you can put on a 348 engine without having to use the high-perf heads? Does Offy make something? I really like the look of the 2x4 setup. Thanks

 

Find a stocker, easy

 

The low-horse 2x4 factory intake should work.
factory 3x2 iron intake would also be a good choice.
Offy does still offer their 2x4 as well, and it only fits the low-horse heads.
-Brad

 

Chevrolet never made a small port dual quad intake for W-Motors only the large port 409's. Offy still makes a nice one for the small port heads.
Max

 

I've heard that you can use the snowflake casting original dual quad intakes on a 348 if you weld up about a half inch of the coolant crossover passage, but I've never tried it myself. I wanted to use dual quads but I settled on a single 4 on my 348.

 

Here is my 348 with small heads and the Offy intake.

 

Coolant crossover isn't a problem but just bolting the intake on is. Besides the HUGE difference in port size the 4 intake bolts,2 on each side, that are over the intake ports are in a different spot. When GM raised the ports for the big valve heads they also raised the holes where these bolts go. As a result the new bolt hole in the intake, actually now a slot, sits much higher than on a small port intake and interferes with the valve cover. Big port heads with their raised ports are taller than small port heads. Over the years many people have used the big port intakes on small port heads by removing the hole/slot on the intake and smoothing the area but this means that you are not going to have those 4 bolts doing their job anymore. The valve covers will now bolt on without interference. Also, there is a HUGE intake port mismatch if you do put this intake on small port heads so power and flow will definitely be lacking. Looks good though.

Max

 

I had a customer that wanted to run a factory 2X4 intake on his standard heads. So I grabbed this old/cracked head and started grinding to see if it would work. It turns out there is enough material in the head to match it to the intake. You gotta be careful, but I ended up port matching the intake ports, cleaning up the bowl under the valves and putting bigger valves in the heads. It wasn't real cheap, but it seems to work pretty well. Like Max says, you gotta fill the bolt holes inbetween the ports, but it didn't seem to give any problems.
Larry T

 

Thanks for the input on the 348. Looks like I will start with finding a stock engine. Thanks

 

I used the 400 hp alluminum snow flake on my 348 with the 333 truck heads worked great the ports dont line up at the top and I could not use the center bolt holes.
No matter with a set of high perf gaskets bolt her on and worked like a charm.