Air induction; hood scoops

[someotherguy]

Won't you have to change/modify the core support for the wider 7.4L radiator?

No, just as 454CID mentioned if you have the narrow radiator you'll need the wider shroud pieces, too. The core support has spots for the rubber isolators for either width radiator, and the upper mounting spots for the isolators are part of the shroud.

Richard

 

[Supercharged111]

Is that the lip on the butterfly edge? Even if not - what is its purpose?



Thinking back to when I was working at the front of my truck (when photo was taken) I think I took a squint into that 'hole' and didn't deduce that was the air feed to the air box as it didn't seem to lead towards it. I guess though that that's what it must be and that GM must have given it some thought.
Isn't it a bit vulnerable to water ingress during fording? Or is it expected that a snorkel would be used if fording was the intention?

The lip on the butterfly is there to dull throttle response for people who suck at modulating the throttle. Basically makes it progressive, but if you get rid of it the truck lugs its own ass around with less throttle input. Not everyone likes it but if you're running heavy it's very helpful. As far as the truck sucking in water, I've been through quite a bit and not had an issue. I suppose it could be an issue, but you'd need a lot of water often for it to really be an issue.

 

[Pinger]

The lip on the butterfly is there to dull throttle response for people who suck at modulating the throttle. Basically makes it progressive, but if you get rid of it the truck lugs its own ass around with less throttle input. Not everyone likes it but if you're running heavy it's very helpful. As far as the truck sucking in water, I've been through quite a bit and not had an issue. I suppose it could be an issue, but you'd need a lot of water often for it to really be an issue.

Cheers.
Does the lip slide off and on so that I can try without it and replace it if I prefer it as standard?

I wondered if it wasn't for fairer distribution of air between all the cylinders. Are some manifolds better than others for this - or are we looking at manifolds for carbs for this?
Of interest to me due to my LPG (propane) system behaving like a carb to some extent. The LPG is entering well upstream as vapour (unlike gasoline which is partial vapour at best) so doesn't suffer the inertial effects of raw gasoline but as I'm probably going to be changing my inlet manifold gasket,I'm looking for any improvements that I can make while I'm there. My guess though is that a change of manifold will bring with it a whole bunch of snags in fitting it. Any thoughts?

 

[Supercharged111]

The blade itself is riveted on so you could drill out the rivets and plug the holes to see what it's like without. 454 throttle body blades lack the lip, same diameter, but they do have actual progressive linkage.

 

[df2x4]

Just putting this out there as someone who removed the throttle blade lip on a V6 truck. It sucks. Turned my throttle pedal into an on/off switch. I put a factory blade back on. I've never done it on a V8 truck but I can't imagine how people enjoy it.

And no, I don't suck at modulating throttle (try driving my Monte), I just prefer it to respond in a linear manner.

 

[Supercharged111]

V6 had a bigger lip than a V8 too.

 

[TheAutumnWind]

It looks like you have a 98 350.... that factory airbox was designed to be enough for my 454. If it were me, I'd make sure my cooling system was good to go, and maybe look at an additional transmission cooler..... there has been some discussion on the forum about keeping the ATF cool, but not too cool. I don't recall the details on that, However.

An 11 blade composite fan might be a nice upgrade. I just bought one through ebay, but here is the info from Rockauto

https://www.rockauto.com/en/moreinfo.php?pk=887449&jsn=3

trucool 40k is a killer trans cooler and has a bypass at low temps.

 

[TheAutumnWind]

Yeah, if you are thinking about "keeping cool" focus on cooling system. Fluids are way better at transferring energy, in this case, heat from a thermodynamic perspective than air.

Where an air-cooled engine would be better than water-cooled would be simplicity. That's it. I mean, you don't have a VW Beetle under your hood, right?

If you have the towing option from the factory, then you have engine oil cooler, transmission cooler and power steering cooler. If not, then add those.

These GMT 400s worked/work very well for towing and hauling. About the only improvement I can think of is using a 7.4 radiator, as that was thicker.

Maybe compare cooling system to 3500HDs GMT 400. Those trucks were like GVWR of 15,000 lbs, and a lot of them were equipped with 5.7s.

Put some new coolant and inspect hoses and check thermostat/radiator.

The HD trucks do get a thicker radiator.

See comparison of my stock 28" vs HD 34". The core is twice as thick.

You must be registered for see images attach

 

[TheAutumnWind]

Won't you have to change/modify the core support for the wider 7.4L radiator?

Edit: And the fan shroud?

I made the bigger thicker rad fit on my 4.3l rcsb with no mods to the core support. Trimmed shroud. Purchased upper rad mounts.

Heres the rad I installed. Total overkill for the 4.3 of course.

https://www.amazon.com/gp/product/B000C7VZGY/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1

 

[Pinger]

Does anyone know off the to of their head what diameter the narrowest part of a 5.7 Vortec's throttle body is? Still trying to figure out if my LPG mixer is restricting flow. Its ID is 45mm.