'99 4.3 vortex swap '84 c10

[cfan10]

Meant to write vortec

I know that to do the swap, I need another intake manifold if I decided to carb it. Is it difficult to use it as fuel injection in an 84 c10 original 305/350.
I plan to use the 4l60e as well, wondering about the driveshaft from the c10 mating up to the 4l60e. Also, questions about motor mounts/cross members?
Have the entire blazer to pick parts from.
Is there anyway to use the rear disc brakes from the blazer rearend on the c10? Better braking with the disc brake setup, running the same size tires on both vehicles 235/75/15

A quick walkthrough of the process of this would be greatly appreciated. Thanks as always in advance.

I just want reliability of the 4.3 in my c10 and of course the saving of gas is a factor. Blazer was hit in rear nothing major just cracked the bumper. I don't want to go out junking and buy an engine for the truck that I know nothing about. I'd rather go with is proven.

Info
84 c10 305/350

Recently new parts

4 barrel carb
Electric fuel pump
Alternator
Starter
Hei distributor

[cfan10]

Forgot I have dual flowmaster straight pipes on the c10 now, would like to use those on the 4.3 too

[DieselSJ]

IMHO, losing 40+ cubic inches is not the way to reliability. EFI makes the 4.3 reliable, so swapping out for a carb isn't the way to go. The 4L60E is electronically controlled, so what is the plan to control that if you swap to a carb?

If you want to swap it in, do the whole package and keep the EFI.

Personally, I'd sell off the Blazer and use the money to fund a later model EFI engine/transmission swap. You don't need to get as crazy as a LS. I nice later model 5.7 TBI/4L60E swap would go in with minimal effort.

[chuychevy82lwb]

I say go lsx there cheap, easy to install good on gas reliable and they male parts for days for these trucks i wiring aint bad if you know even basics

[daddyjeep]

I am doubtful that the 4.3 would save you any money at the gas pump. The smaller motor is going to have to work harder to keep your heavy truck rolling. I take it you are having problems with your current 305?

[cfan10]

Yep 305 spun a rod on trip from humble to new orleans going to check on my dad. Could possibly switch out crank and bearings but doesn't make much sense. I want to run the 4.3 with 4l60e using efi. I know the 4.3 can bolt up to the th350 transmission I currently have in the truck.

My question is what will I need from the blazer because it has some body damage in the rear. I don't want to spend money on another efi engine when this one is free and clear and runs excellent ac is ice cold.

It wouldn't make sense to sell the blazer at best for a few hundred. My dad is sick and not really able to physically do the work with me. I have an associate degree in automotive technology. So, I feel ok about this but the wiring is kinda scary.

Thanks for all the answers!!

[cfan10]

C10 is not being built for possible resale just reliable cruiser for my family. So, 5.3 or 6.0 while great are not the direction I want to go. The idea is to use what I already have on hand.

[74CustomK20]

It can be done. I think the v6 will have to work harder but the fuel injection will compensate for it.

[daddyjeep]

Since you have both on hand it should be pretty straight forward to physically get the 4.3 between the frame rails and see what you need to do for mounts and such. The wiring shouldn't be too bad. Get yourself some schematics and take your time. I am not a wiring guy, but with some patience and time spent reading schematics I was able to wire in a MPFI 5.2 into my Jeep.

[tucsonjwt]

I bought a new Silverado work truck in 2000 which had a 4.3 and automatic transmission. It was fairly quick from a stop but could not handle a heavy load very well. As long as you are not planning on carrying heavy loads or towing a lot it should be fine. I got 19-20 city/24-25 highway with the 2000 truck, but I drove very carefully.

[MalibuSSwagon]

http://lt1swap.com/96-99_vortec_harness.htm

Youre welcome He will also do re-programming for $75 plus shipping to him.

My suggestion.

Get mounts from a V6 C10, and drop engine in. You may need to move the trans crossmember to use the 4L60E. Wiring should be fairly easy to standalone, your best bet is to use the factory blazer fusebox and wire in the power circuits. If you can keep the blazer until the C10 is done and running, in case you need anything off it. Best part is you can repin the harness later and re-flash the PCM if you want to put in a Vortec V8.

If that's a bit daunting, Howell can provide you with a new harness for $550 which is not bad for an all new harness.

[cfan10]

Quick question on the motor mounts is 88-98 v6 truck mounts compatible with the original cross member in the c10...thinking finding v6 c10 with be an issue at the junkyards. Thanks.

[Tilt]

I LS swapped my 86 which started with a V-6. I may still have the mounts. I'll try to remember to look tomorrow before I come back to work.

[D13]

Since these trucks came with 4.3 / 700R4 for a few years, everything to bolt the engine and trans in is available. Just have to mount the ECM and get rid of VATS etc.

[Clyde65]

I had an 85 with the 4.3/700 combo and usually only got 16-17 mpg. I currently have a 4.8/4l60e and consistently get 19mpg. Just food for thought.