305 Swap To ???

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.

85longblack

Junior Member
Joined
Jul 7, 2023
Posts
2
Reaction score
4
Location
Roanoke, Virginia
First Name
John
Truck Year
1985
Truck Model
C10
Engine Size
5.0
Hello. New guy here. I recently bought a 1985 C10 with the 305 (sadly). I do not want to jump on the LS bandwagon (no offense) but I do want to swap it out for something beefier. I am not looking to drag race and the truck will not be a daily driver. It is a toy for me and the wife to cruise in. Are there any major benefits to using a Vortec set up as opposed to ordering a somewhat built 350? How difficult and expensive is the Vortec swap? Thanks for any help.
 

Shorty81

Baby Boomer
Joined
Mar 19, 2018
Posts
2,883
Reaction score
5,135
Location
North West ohio
First Name
Darren
Truck Year
86
Truck Model
K20
Engine Size
496
Welcome from Ohio. I'm old school, I'd recommend big block. I'm old, drive around gently and my 496 is surprisingly better on fuel than my last truck with a 350.
 

Attachments

  • IMG_20171124_150352.jpg
    IMG_20171124_150352.jpg
    108.2 KB · Views: 44

SquareRoot

Full Access Member
Joined
Mar 18, 2017
Posts
3,705
Reaction score
6,699
Location
Arizona
First Name
Mike
Truck Year
85
Truck Model
K20
Engine Size
350
I have Vortec. I wouldn't do it again. For the money there are better options. If you have a 700 trans, you have two issues.
 

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
2,887
Reaction score
6,489
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
I also would recommend a BB. When I pulled the 305 out of my '82 I slipped in a 1971 402 BB. Bored .030 over made it about a 406. Mild RV cam made it a torque machine.

Many BB's to chose from and they slip right in. You need different rubber engine mounts and they bolt to different holes that are already in the cross member you have.

Best to get an engine that still has the engine accessories, ie the PS pump, alternator etc, as the brackets are not the same as the small block.
 

RecklessWOT

Full Access Member
Joined
Feb 20, 2015
Posts
2,549
Reaction score
4,744
Location
New Hampshire
First Name
Kevin
Truck Year
1987
Truck Model
V10 Suburban Silverado
Engine Size
350 TBI
Vortec engines are decent, but they're nothing so amazing that I'd go out of my way to swap in. Getting a beefed up crate 350 is the easiest most straightforward thing you can do. Pull that 305 out and use it as a boat anchor (or sell it to someone who needs to run one for their class of racing), slap the crate motor in and call it a day.

Though like others have said, I too personally am a fan of big blocks (and just like you I am not fond of LS swaps). It's all up to you, but yeah I wouldn't waste the time/money going with a vortec, they're good engines for what they are and sure there are some advantages, but a built regular 350 would be awesome and your easiest/cheapest route.
 

85longblack

Junior Member
Joined
Jul 7, 2023
Posts
2
Reaction score
4
Location
Roanoke, Virginia
First Name
John
Truck Year
1985
Truck Model
C10
Engine Size
5.0
I had honestly not given much thought to a big block but
all of your comments make perfect sense. All I know for sure is that 305 has to go!
 

tadslc

Full Access Member
Joined
Jan 20, 2020
Posts
109
Reaction score
104
Location
Birmingham, AL
First Name
Tad
Truck Year
1981
Truck Model
C10
Engine Size
305
I am in the process of changing out my 305 and went with a crate 350. Absolutely the simplest, least expensive option.
 

84c10Tony

Howdy!
Joined
Apr 14, 2017
Posts
145
Reaction score
122
Location
In but not from So Cal
First Name
Tony
Truck Year
Was 84
Truck Model
c10
Engine Size
305
I am not looking to drag race and the truck will not be a daily driver. It is a toy for me and the wife to cruise in.
If you would like some great info...check out Rich Weyand's posts here, awesome intelligent guy with common sense.

"Simplicity and Torque".

My ol' 84 with a 305/700r4 cruised just fine, (even better with a Detroit Tru-Trac and 3:73's). Got 18mpg right off the bat during break in.
Best was 22mpg with tailgate between 45-60 deg.

The 3:73's Really woke up the 305, I can almost imagine running it with an RV cam, intake and long tubes.

I would have enjoyed Rich's suggestion for the win...I didn't get to it.
Growing up around hot rods in east Detroit, cruising Gratoit Ave etc., in mild to wild, his idea for low cost basic fun is the best I have seen.

How ever one looks at, Enjoy!, we only get so much time, so much money.
 

Asgeir

Junior Member
Joined
Oct 22, 2022
Posts
29
Reaction score
39
Location
Nowhere, Oklahoma
First Name
Coty
Truck Year
1984
Truck Model
C10
Engine Size
383
I was in the same boat, for my 84, it had a 305 that was dead. Got a 350 SB TBI from a 87 and made it a 383. I was 50/50 on the LS swap, wanted to keep it old school.
 

potent rodent

Full Access Member
Joined
Mar 22, 2020
Posts
193
Reaction score
111
Location
indiana
First Name
butch
Truck Year
86 and 78
Truck Model
1500
Engine Size
350 and 305
i would go 383 a lot cheaper to build than a big block, trust me i know from experience.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
4,068
Reaction score
5,924
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
So you're not going to drag race it,you do want to cruise in it. Buy a rust bucket 5.7 tbi burb,swap gas tank, wiring,engine and rear end, small cam,underdrive pulleys,headers,electric fan. Decent milage excellent drivability,and enough balls to tow with. Yea not all burbs had better rear gears but 10-1 you're going to end up with better gears. This is really a dirt simple swap
 

quaddriver

Full Access Member
Joined
Sep 1, 2015
Posts
55
Reaction score
5
Location
Cook Forest PA
First Name
Ed
Truck Year
1990
Truck Model
Chevy R2500
Engine Size
The big one
Is GM still selling the toluca 350 drop in (check out jegs and summit or jim pace) that makes 260? hp using duals and a 4bbl - something that will be childs play, even if you install 2 cats.

the L31 head vortecs tho...you cannot beat the breathing without going LS or spending twice (or more ) the budget on foreign heads for a gen1 SBC. not a single pair of the gen1 heads flow worth a damn without 20 hours under a grinder, humps and casting proofs be damned

your best bang for the buck will still be a boneyard LS...they make more power just sitting there and you can install dizzys and carbs all day and in case you wanna go EFI everyone is flashing. I just inherited a '13 GMC WT with the 4.8 that makes more factory hp than every SBC ever installed in a truck and most that were installed in a car. hard to say no...

someone mentioned the 700R4...85 was a magic year where the pump was beefed up but there are more mods SINCE that you will want and most are DIY if you have a few tools lying around.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
4,068
Reaction score
5,924
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Big block small block ls, will always be a debate. Naturally aspirated. a very mild 454 makes more horsepower and torque than a factory ls1 ls2 ls3 ls 6. Nothing complicated about the swap. No modifications neccesary. As for reliabilty I guess people don't remember thousands of people each year used to jump into big block motor homes, and drive them across country with out fear.
 

Latest posts

Forum statistics

Threads
42,140
Posts
910,033
Members
33,642
Latest member
Bhardiman1
Top