Anybody had their SBC swap done by a shop/individual?

arlowf

Apprentice
Thread starter
Feb 11, 2022
81
8
My best piece of advice is to be very specific about the details with whoever is doing the work and put it in writing. You said you're getting a running engine out of an old truck and the intake manifold in your cart indicates it's a lat 80s - early 90s TBI. I saw no mention of resealing, degreasing, or detailing the engine before it goes in your car. If you're only expecting "just slap a tree-fiddy in der", then you probably won't be disappointed. A 4.3 -> 5.7 isn't a direct swap but it's close. There will be some predictable speedbumps -- always are.



I'm in no way trying to talk you out of it. Just want you to have reasonable expectations.
5.7 is being put in with a carburetor. It's tbi now.
The advice about getting details in writing is good advice though. Thank you.
Any plans on the fuel delivery system modifications you'll need in this swap?
This might account for the added time some people have questioned.
Switching to a performance mechanical pump that cost a whopping $40 bucks lol from summit. More than adequate and I watched a YouTube dyno test using the same pump.
I’d keep at least another 1000 aside for the stuff no one thought of .
don’t let these guys make you feel bad for not wanting to do it yourself .
Your car ,your life ,you know what you want
Also , I’ve fixed a lot of stuff homeowners have done on their own home because “it’s easy - just watch a YouTube video and do it “ lol
I’ll pound nails cause I’m good at it and I’d pay a mechanic to do a motor swap because he’s good at it .
And yes I have done several swaps myself ,scratches on frame, header panels and firewalls to prove it
Not to mention pinching starter cable in motor mount putting me on side of freeway at 1am
Or wondering what that little black box does , then drive to buddy’s place and explode the battery all over the trunk

Paying someone a couple grand to do something they are good at, as opposed to doing it myself and not getting to drive it for 2 months as I find time on weekends is a no-brainer for me. I've done all my own body work and electrical and reupholstering. Someone else can drop the engine in for me.
 
  • Like
Reactions: 1 user

arlowf

Apprentice
Thread starter
Feb 11, 2022
81
8
Now, here's something else to consider. If your 4.3 runs okay, why not work from the other direction? A rear gear change will make a huge difference in how the car feels. My 305 is rated with roughly the same power numbers as your 4.3 and going from my hella lame 2.29s to 3.42s felt like a 100hp bolt on. You could do a gear swap and add limited slip at the same time and change the whole personality of your car. Upgrading to 28 spline axles would be a good idea as well.

The next upgrade would be a nicely built overdrive. Snappy shifts and a bit more converter will make the car feel even more zippy.

Then you have a 400hp/400lb-ft drivetrain instead of a 250hp/250lb-ft drivetrain. You can build a nice healthy SBC without worrying about the parts downstream.
You're telling me your 303 puts out 140HP, really?
 

Ribbedroof

Comic Book Super Hero
Supporting Member
Jan 4, 2009
4,541
113
Wellston, OK
Switching to a performance mechanical pump that cost a whopping $40 bucks lol from summit. More than adequate and I watched a YouTube dyno test using the same pump.
Lot of those TBI engines aren't machined for the mechanical pump pushrod. You may have to go electric. FYI, all those Mr Gasket/Edelbrock little square pumps regularly fail in under a year. Boss just replaced one in his Chevelle, despite my recommendation of replacing it with a better pump.

You're telling me your 303 puts out 140HP, really?
Yep. malaise -era 305s are 120-140 HP as delivered.
 
  • Like
Reactions: 3 users

doood

Amateur Mechanic
Sep 24, 2020
264
93
So I'm going to ignore the "buy a crate motor" comment from the previous post (nor by you), because I plan on having this engine for 15 months in there before having the heads rebuilt and the cam swapped for another $2,500. And it's a 5.7l from a 96 Chevy 2500....
Why carburetor when the car and swap motor are both fuel injection?

It's a core return!?! Rebuilt L31 long block is < $1500.
 

08Malibu

Royal Smart Person
Feb 9, 2014
1,130
113
North Jersey
Now, here's something else to consider. If your 4.3 runs okay, why not work from the other direction? A rear gear change will make a huge difference in how the car feels. My 305 is rated with roughly the same power numbers as your 4.3 and going from my hella lame 2.29s to 3.42s felt like a 100hp bolt on. You could do a gear swap and add limited slip at the same time and change the whole personality of your car. Upgrading to 28 spline axles would be a good idea as well.

The next upgrade would be a nicely built overdrive. Snappy shifts and a bit more converter will make the car feel even more zippy.

Then you have a 400hp/400lb-ft drivetrain instead of a 250hp/250lb-ft drivetrain. You can build a nice healthy SBC without worrying about the parts downstream.
I agree. I went from 2.41 to 3.08 and it was the best mod I’ve done. My 160hp 305 woke right up. Can’t wait to slap in my 260hp L31.
 
  • Like
Reactions: 1 users

oldsmobile joe

Royal Smart Person
Nov 12, 2015
2,044
113
mpls
Switching to a performance mechanical pump that cost a whopping $40 bucks lol from summit.
You're right. But thats the easy part. But more importantly, what about the rest. You have an intank pump, mechanical pump won't suck fuel if that pump is in the way. Do the fuel lines run down the passenger side like carburetor cars? If not, you'll need a work around. Will the v8 have a spot for a mechanical fuel pump? If not, you'll need a work around on that too. Do you have a lock up torque converter? You'll need a work around on that if you want it to work. What are you going to do for a choke? Electric or cable will need a work around since that is currently controlled by the computer. Do you have a v8 radiator and hoses? More work.
Swapping the motor is easy, I've done it under 3 hours.
Its the details that take time. All these work arounds take time.
Time is money.
Thats why he's charging what he is. He's running a business not a hobby.
Just my $.02.
 
  • Like
  • Agree
Reactions: 3 users

565bbchevy

Geezer
Aug 8, 2011
9,275
113
Michigan
So I'm going to ignore the "buy a crate motor" comment from the previous post (nor by you), because I plan on having this engine for 15 months in there before having the heads rebuilt and the cam swapped for another $2,500. And it's a 5.7l from a 96 Chevy 2500. The guy got it as a core charge at his shop when he did an engine swap for someone else.
The advantage of a crate engine regardless if you install it yourself or pay someone a lot of money to install it is you are starting off with an engine that has been completely rebuilt with new parts at the power level of your choice and many come with a warranty and dyno sheet.
While the initial cost for the engine will be more you are only paying the shop for the R & R and whatever mods are needed for the install instead of paying for labor twice on the same $500 core engine that has no warranty and you probably don't know the history or maintenance of either.
As far as installing an engine by yourself, I have done it dozens of times and mostly with big blocks, SBC's are even easier.
 
  • Agree
Reactions: 3 users

08Malibu

Royal Smart Person
Feb 9, 2014
1,130
113
North Jersey
You're telling me your 303 puts out 140HP, really?
The 86 305 in my Malibu is rated at 160 from the factory.
I have 2 truck engines sitting right now, a 97 and 98. The 97 is drilled for a fuel pump, the 98 isn’t. You will know if it’s drilled if it has a block off plate bolted to the block.
My car was originally a 6 cylinder car. I swapped it years ago to the 305. It wasn’t too bad. I think in your case the mounts might be the same since you have a 4.3. Biggest hurdle is the wiring.
 

Ernest

Master Mechanic
Apr 28, 2016
388
63
Texas
The greatest satisfaction for any gearhead is having done the work themselves... they learn more about what it takes to get things running, but its not witout its challenges, especially swapping unlike engines.

Luckily i've been into cars for over 30yrs, so consider me a major gearhead, and NOONE touches my car(s) but me.
 
  • Like
Reactions: 2 users

arlowf

Apprentice
Thread starter
Feb 11, 2022
81
8

That's the fuel pump. Going mechanical because we are going carbureted instead of TBI (hence the manifold swap) for HP reasons.
You can get to 375hp very cheaply with port and polished Vortec heads, a 600cfm carb, and a mild cam on a 5.7l.

For those asking very specific questions about how the fuel line is going to be routed/etc... he's done this exact swap before (4.3 TBI to 5.7). He knows what he's doing. He had this exact car.
That's why I'm paying good money for him to do it with budget parts. Not garbage, budget. A used block is in no way garbage, and nothing about my setup should cause it to fail early. The heads, gaskets, cam; all getting replaced within the next 6-12 months.

I'll post pictures of before and after. I'll update this thread after this is all done in 4 weeks. Then everyone can tell me how wrong I did it :)
Or maybe, just maybe, I'll have a fun daily streetable driver I'll be driving through the summer then putting back in the shop in September.
 
  • Like
Reactions: 1 user

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact Admin@GBodyForum.com for info on becoming a sponsor