Any way to enable control over the drive-overdrive shift point?

[95Noobie]

I'm going to show my ignorance but is a 383 a bigger small block engine size option?

I'm thinking the work of replacing front and rear axle (sourcing the axle, probably used with the proper gears) and installing might be about as much work as getting the motor swapped? I have the 3.73 gears (GT4 on the RPO code) and it seems just about right for trying to squeak out a bit better highway mpg if the engine didn't lug. I assume if we did a 350 it would have a bit more power so that when your torque converter locked in the 'overdrive' situation the engine could more easily move it out of the lugging stage to the higher rpms without unlocking the torque converter to get some speed.

on paper the 350 horsepower rating vs the 305 is not much different but I'm hearing from all of you that it makes a big difference in real life. I think I need to find a truck with the 3.73 and the 350 and give it a test drive to see what difference it makes.

My 305 may be 'tired' or have some loss of compression. I have not checked compression on all 8 cylinders. I have just focused on fuel system, injection cleaning, getting sensors working, plugs, wires, general tuneup.
I have so much to learn. I saw a 1995 used truck that could be a donor but it had a 'rebuilt' 350 with terms I wasn't familiar with and with some type of turbo looking swoopy thing instead of the usual air cleaner as part of a cold air intake system and what looks to be a throttle body spacer. Would finding a way to get more air down into the lungs of my engine help? I'll attach the picture. (and below is the for sale ad which lingo you'all probably are familiar with)

================================
-Engine rebuilt at 189,000 miles
•RV cam•Edelbrock intake
•.030 over flat top pistons
•double roller timing chain
•high volume oil pump
•throttle body spacer
•cold air intake
•new starter
•new water pump
•new radiator

-Transmission rebuilt rebuilt at 189,000 miles•shift kit•high performance torque converter •Autometer trans temp gauge •heavy duty transmission cooler

-2019•10 bolt rear axle replaced with 14 bolt semi-floater. New bearings and seals.•rebuilt front and rear driveshafts •all new u-joints•New front wheel bearings

You must be registered for see images attach

 

[95Noobie]

I think I can glimpse what they might call 'shorty headers' on the driver side where the manifold would be?

 

[NickTransmissions]

(and below is the for sale ad which lingo you'all probably are familiar with)

Did you google each of the terms/lingo you are unfamiliar with, including what a 383 is and how it compares to a 350?

 

[95Noobie]

yes, working on it. I can't make out the name on the 'turbo swirly thing' in the picture to google that. is it 'Kiraid'?

 

[Supercharged111]

Airaid

 

[95Noobie]

So it appears folks here are not fans of custom cold air intakes...

 

[Sean Buick 76]

It’s an “air raid” brand intake and from what we can see the owner “may” be truthful about the engine and trans rebuild but it’s tough to tell without tearing it down. Actually a good boroscope down the spark plug hole could give you a good indication if the pistons are indeed flat tops or not.

A 350 it very similar to the 305 just with a block which has a larger bore diameter.

 

[Supercharged111]

So it appears folks here are not fans of custom cold air intakes...

If they're actual cold air intakes sure. Most are not.

 

[95Noobie]

I'm curious how to truly get 'cold' air into a 'cold air' intake. I can see the factory plumbing leads over to the passenger fender area but even the stock setup is not sticking into the fender area far enough to truly suck in only outside air. There is a fairly sizable gap into the engine bay that i'm sure is bleeding warm air into the intake stream. Is there a preferred modification to maybe direct the piping towards the back side of the radiator pointing the intake in the forward direction so air 'rams' straight into the air filter? Or maybe direct the plumbing down and then straight forward once under the engine where unobstructed air is flowing under the truck? I feel getting more air through the engine will help just based on how the engine sounds/runs with the air cleaner lid open. I also understand the need to not flip the air cleaner lid or other things that would suck water or dirt into your engine.