84 Chevy P30??? Anyone know anything??

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

SDJunkMan

Full Access Member
Joined
Nov 17, 2017
Posts
1,794
Reaction score
2,632
Location
Black Hills of South Dakota
First Name
Jeff
Truck Year
1978
Truck Model
K10
Engine Size
350
I got a P30 based motorhome running to sell, and the engine and transmission were excellent. It had a TH400 so I would imagine yours also does. I couldn’t imagine it having anything else. Also, I think they’re talking about a Gear Vendor unit so instead of having three speeds, it would have six. Mine didn’t have that, however.
Yeah, a gear vendor overdrive, that's what I was trying to think of. It is a two speed that mounts behind the tranny and usually gives you a direct and overdrive.
 

deve05

Full Access Member
Joined
Dec 28, 2017
Posts
160
Reaction score
50
Location
US
First Name
Diego
Truck Year
1984
Truck Model
c10
Engine Size
305 C.I.
Yeah, a gear vendor overdrive, that's what I was trying to think of. It is a two speed that mounts behind the tranny and usually gives you a direct and overdrive.
Is that something that would work in a light duty application or not really?

Sent from my Moto Z (2) using Tapatalk
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
9,786
Reaction score
9,672
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
The engine is likely accessed from inside the motorhome, you will have to remove the "doghouse". I'm certain you could find the answers to many questions you have by doing so.

There is an engine access hole between the two front seats.

The trans is very likely a th-400 which will be an extremely strong piece of gold, as may be the block. I give it 50/50 on an overdrive but that's probably generous.
 

nvrenuf

Full Access Member
Joined
Jul 30, 2010
Posts
1,721
Reaction score
1,930
Location
Mobile, Al.
First Name
John
Truck Year
1991
Truck Model
K5
Engine Size
454
The engine block casting number is not a guarantee tell if it's a 2 or 4 bolt, some castings can come either way. You may have to pull the oil pan or timing cover to be sure.
 

deve05

Full Access Member
Joined
Dec 28, 2017
Posts
160
Reaction score
50
Location
US
First Name
Diego
Truck Year
1984
Truck Model
c10
Engine Size
305 C.I.
The engine is likely accessed from inside the motorhome, you will have to remove the "doghouse". I'm certain you could find the answers to many questions you have by doing so.

There is an engine access hole between the two front seats.

The trans is very likely a th-400 which will be an extremely strong piece of gold, as may be the block. I give it 50/50 on an overdrive but that's probably generous.
Gold you say?? Lol thats what I wanna hear because both the transmission and dually rear end I'd be selling. I have no use for a 3 speed auto trans in what will be a 6 speed truck.

Sent from my Moto Z (2) using Tapatalk
 

SDJunkMan

Full Access Member
Joined
Nov 17, 2017
Posts
1,794
Reaction score
2,632
Location
Black Hills of South Dakota
First Name
Jeff
Truck Year
1978
Truck Model
K10
Engine Size
350
Is that something that would work in a light duty application or not really?

Sent from my Moto Z (2) using Tapatalk
I have heard guys talk about putting them in their trucks, but I have no personal experience. What kind of 6 speed are you planning to use?
 

deve05

Full Access Member
Joined
Dec 28, 2017
Posts
160
Reaction score
50
Location
US
First Name
Diego
Truck Year
1984
Truck Model
c10
Engine Size
305 C.I.
I have heard guys talk about putting them in their trucks, but I have no personal experience. What kind of 6 speed are you planning to use?
Well i would ideally like to use a T-56 from an f-body. But i have yet to do any kind of research on weather or not the gear ratios will put the 454 in power after every shift. All i know is i dont want the end product to be auto and i want 5 or 6 gears not 4.

Sent from my Moto Z (2) using Tapatalk
 

73c20jim

Full Access Member
Joined
Jun 11, 2018
Posts
2,282
Reaction score
2,924
Location
Tombstone, AZ
First Name
Jim
Truck Year
1973, 1973
Truck Model
C20 2WD Custom Deluxe. C10 2WD Base Model
Engine Size
350 CID 195/260 HP Goodwrench crate, 400 CID 2bbl
I believe 5th is .75 and 6th is .50 overdrive. Been a while.
 

deve05

Full Access Member
Joined
Dec 28, 2017
Posts
160
Reaction score
50
Location
US
First Name
Diego
Truck Year
1984
Truck Model
c10
Engine Size
305 C.I.
I believe 5th is .75 and 6th is .50 overdrive. Been a while.
Thats something that I'm dying to learn. How to calculate gear ratios and final drive to figure out engine rpm in a given gear. If you know how to do it I'd love to hear it!

Sent from my Moto Z (2) using Tapatalk
 

deve05

Full Access Member
Joined
Dec 28, 2017
Posts
160
Reaction score
50
Location
US
First Name
Diego
Truck Year
1984
Truck Model
c10
Engine Size
305 C.I.
While i'm thinkin about it...the radiator could be worth a fortune also!
I guess all I'd need is someone interested in buying all this stuff! I dont imagine any other use for it other than someone tryna bring one back to life.

Sent from my Moto Z (2) using Tapatalk
 

deve05

Full Access Member
Joined
Dec 28, 2017
Posts
160
Reaction score
50
Location
US
First Name
Diego
Truck Year
1984
Truck Model
c10
Engine Size
305 C.I.
Put it in your truck, Dave...

xc_hide_links_from_guests_guests_error_hide_media
Lmfao [emoji23][emoji23][emoji23][emoji23] I'll let you know.

Sent from my Moto Z (2) using Tapatalk
 

73c20jim

Full Access Member
Joined
Jun 11, 2018
Posts
2,282
Reaction score
2,924
Location
Tombstone, AZ
First Name
Jim
Truck Year
1973, 1973
Truck Model
C20 2WD Custom Deluxe. C10 2WD Base Model
Engine Size
350 CID 195/260 HP Goodwrench crate, 400 CID 2bbl
Thats something that I'm dying to learn. How to calculate gear ratios and final drive to figure out engine rpm in a given gear. If you know how to do it I'd love to hear it!

Sent from my Moto Z (2) using Tapatalk

Need to know engine RPM.

Need to know transmission gear ratio, including any extra overdrive, if any. (To convert engine RPM to driveshaft RPM.)

Need to know rear end ratio. (To convert driveshaft RPM to axle RPM.)

Need to know LOADED tire radius from center of hub to ground with tire at proper psi. (To convert axle RPM to number of ROLLING circumferences in inches. C = pi D. Then convert these inches into miles. 5280 ft =
1 mile. 5280 ft x 12 inches per foot = 63360 inches per mile.)
Also have to convert revolutions per minute to revolutions per hour. (60 minutes per hour.)

Need to know MPH.


If you have any four, you can calculate the other.

And you said you would never need algebra.

Pretty sure this is right, Been a long while.
 

deve05

Full Access Member
Joined
Dec 28, 2017
Posts
160
Reaction score
50
Location
US
First Name
Diego
Truck Year
1984
Truck Model
c10
Engine Size
305 C.I.
Need to know engine RPM.

Need to know transmission gear ratio, including any extra overdrive, if any. (To convert engine RPM to driveshaft RPM.)

Need to know rear end ratio. (To convert driveshaft RPM to axle RPM.)

Need to know LOADED tire radius from center of hub to ground with tire at proper psi. (To convert axle RPM to number of ROLLING circumferences in inches. C = pi D. Then convert these inches into miles. 5280 ft =
1 mile. 5280 ft x 12 inches per foot = 63360 inches per mile.)
Also have to convert revolutions per minute to revolutions per hour. (60 minutes per hour.)

Need to know MPH.


If you have any four, you can calculate the other.

And you said you would never need algebra.

Pretty sure this is right, Been a long while.
Wow, thank you! Im gonna grab a pen and paper and see if i can figure it out.

Question, does differential gearing affect this at all! Like 4.10 vs 3.73. Because it affects speed vs engine rpm.

Sent from my Moto Z (2) using Tapatalk
 

Latest posts

Forum statistics

Threads
42,107
Posts
909,225
Members
33,593
Latest member
shake1969
Top