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How to swap in a vortec 350 with a carb into a '90 k1500?

Jorge6.5

Jorge6.5

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I hope this is the right section for this, if not please move.

The current motor in my '90 K1500 has a knock in the lower RPMs.

I would like to replace the motor with a newer vortec style 350 motor but at the same time I would like to convert the vortec 350 to a 4 barrel carb.

What's all involved with this swap conversion? What will I need besides the motor and carb?

Thanks
 
If it was me, I'd be looking at a complete Edelbrock intake assembly. Of course I'd also be dropping in an old school HEI ignition while I was at it.

Sent from my SCH-I535
 
Jorge6.5 said:
I hope this is the right section for this, if not please move.

The current motor in my '90 K1500 has a knock in the lower RPMs.

I would like to replace the motor with a newer vortec style 350 motor but at the same time I would like to convert the vortec 350 to a 4 barrel carb.

What's all involved with this swap conversion? What will I need besides the motor and carb?

Thanks
Click to expand...

Go for a carbed 6.0 imo, same bell housing pattern, lots of aftermarket, and 300hp stock.

Source Unknown
 
It's a bolt in install for the most part. Your bottom end is already basically the same(except for pistons and camshaft) as the vortec 5.7L. You will have to buy the special mellonized distributor gear if you run the stock VORTEC camshaft as it is a billet roller cam and the stock HEI gears will not last long at all. The intake is the expensive part of the swap. HOLLEY, GM, EDELBROCK, and a few others make them, but expect to pay almost $300 for one new. But all of your mounts will swap right over, make sure you get an engine for a stick shift since you will need a pilot bearing(GM didn't drill out the end of the cranks in all engines for a pilot bearing just a word of warning), your current water pump will swap right over, as well as your accessories. You will have to make a few brackets for up top to hold the alternator and A/C compressor since you won't have the intake bolt holes for the brackets. Your current TBI throttle cable should even swap over and work. You don't have a tach to worry about. And buy a cheap return style regulator for your fuel pump to drop it down to 4-6 PSI(you already have a return line, utilize it to prevent vapor locking). A lot of guys have done this swap, and other than the intake and a few brackets it is a drop in deal.
 
Wow, thanks a lot for this info. This sounds very doable.

Where can I source this mellonized gear for the distributor?
 
600 cfm will be good up to around 450 hp. I'd suggest checking with Jegs too. If the carb from the Summit kit is a Holley p/n 0-1850 then it can be tempermental year round. Easy to tweak though. That's why I suggested Edelbrock. I hear they are pretty user friendly.

Sent from my SCH-I535
 
I've heard they are easy to use but I'm sure more expensive. I guess you get what you pay for.

If I can find a similar kit with an edlebrock carb, that would be the ticket.

I'll have to figure out which distributor, maybe summit brand?
 
The mellonized distributor gear is available through GM for the 96-02 trucks if you need the smaller .450 shaft. If your HEI uses a different sized shaft you can either use the GM gear and drill it out, or GM PERFORMANCE makes one already drilled out to the larger size. Most used to use a bronze or poly gear with a roller cam, but GM made there roller cams to use a mellonized gear. It will look just like a regular cast gear for a flat tappet cam, but don't try and run one with wrong gear as it WILL die a horrible rapid death(and may take the cam with it). If you get a complete engine with distributor, you can always just take the distributor gear off of it as it is just a roll pin that holds it on. Also keep in mind the VORTEC is a higher RPM engine, and the VORTEC heads are a fast burn design. SO keep the timing down around 28-30 degrees total to start with, and if you can get a distributor with a higher RPM curve to it(full advance around 5000 RPM's instead of the 3500 that many have).
 
Jorge6.5 said:
I'm thinking of using this for the induction set up, 600cfm should be plenty I think

http://m.summitracing.com/parts/cmb-03-0197
Click to expand...

That kit should be fine so long as you run some sort of header. The stock TBI manifolds were not very good for flow, and would probably limit you with a 600CFM carb. Never used one of those carbs, looks like some sort of HOLLEY knock off without removable bowls. The EDELBROCK carbs if it is the older CARTER AFV style can also be rather tempormental, and don't restart when hot for crap. I've used a few before, and you almost always have to floor them on a hot restart to get em to clear out and fire up(they like to vapor lock). As much as people hate them a good quadrajet is hard to beat, but they are getting scarce and hard to find GOOD ones left around.
 
I would like to run long tube headers and would like an "X" pipe with duals.

I'm not even sure if an"X" is available for the trucks, I will have to search. Might have to be a custom job
 
The vortecs damper pulley sits out farther,because of the crank sensor tone ring. Also vortecs blocks aren't drilled for the water pump bypass. I would try to use the vortec serpentine brackets,and ditch the ac.
 
6.2 turbo said:
The vortecs damper pulley sits out farther,because of the crank sensor tone ring. Also vortecs blocks aren't drilled for the water pump bypass. I would try to use the vortec serpentine brackets,and ditch the ac.
Click to expand...

The balancer is different from the vortec to the TBI trucks. The balancer is cut roughly 1/4" off the snout so it sits in the same spot with the tone ring on. That is why I said he needs to use a TBI balancer. The small bypass hole isn't that big of a deal as I believe you can drill it out and make it functional again. I have done this swap before where I used a 96-02 bottom end with the 87-95 swirl port heads, and it is not that big of a deal. Just use the correct pump and balancer for the accessory drive.
 
I also did a swap, 400 sbc in a 97 truck. I used the tone ring combined with a stock 400 sbc damper. I did not have to cut the damper. I did have to mix two different timing chain gears,vortec bottom,and non roller top. The tone ring won't clear a double roller. Also bolt holes are missing for the timing cover if you would want to install a tin timing cover.
 
6.2 turbo said:
I also did a swap, 400 sbc in a 97 truck. I used the tone ring combined with a stock 400 sbc damper. I did not have to cut the damper. I did have to mix two different timing chain gears,vortec bottom,and non roller top. The tone ring won't clear a double roller. Also bolt holes are missing for the timing cover if you would want to install a tin timing cover.
Click to expand...
You can run a double roller chain with a tone ring, you just have to be ready to pay out the nose for the special 2 piece timing cover that is out there. And you can drill and tap the 2 extra bolt holes into a VORTEC block to run a tin cover, or run it as is(have one running this way, has been for 7 years with no leaks).
 
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