4.3 VS. 5.7 Accessories, Distributors, Motor Mounts, etc.???

[jserr68594]

I am considering swapping my 4.3 out for a 5.7 this winter. I am planning on using a vortec truck engine and I was wondering what parts off my 4.3 will transfer over. I know I will have to get different manifolds, distributor cap, and an ignition module. What else will not be swappable?

Thanks!

 

[Maclin]

Re: 4.3 VS. 5.7 Accessories, Distributors, Motor Mounts, etc.???

It is more than just the distributor cap, you cannot use the distributor from the 4.3 at all. The guts inside are for 6 cylinders and not 8.

 

[wca_tim]

Re: 4.3 VS. 5.7 Accessories, Distributors, Motor Mounts, etc.???

It is more than just the distributor cap, you cannot use the distributor from the 4.3 at all. The guts inside are for 6 cylinders and not 8.

distributor is the same aside from the cap, rotor and ignition module. You can get by with the v6 ignition module if you run more advance at idle to make up for it, but it would be a lot better to get a v8-24 if you can find one for a reasonable price... the distributor that came with my first v6... is currently in the 383 in my boat, 4.3 and 5.7 mercruiser distributors are even the same part number.

You need to use a marine carb and intake, as well as the marine starter, alternator, fuel pump, etc... from the 4.3.

biggest expense will probably be the exhaust, biggest pain in the neck will probably be relocating engine mounts and getting everything lined up - assuming that you have enough room in the engine compartment for everything.

do some searching, lots of folks have been through this...

 

[Maclin]

Re: 4.3 VS. 5.7 Accessories, Distributors, Motor Mounts, etc.???

I should have asked what ignition he is running. So, what igniton are you running? Got a model# or year, etc?

 

[jserr68594]

Re: 4.3 VS. 5.7 Accessories, Distributors, Motor Mounts, etc.???

I have searched quite a bit and have not came up with too many specifics on the swap.

I have the thunderbolt iv ignition. The engine is a 94 4.3 LX.

Can I reuse the following items?:

-Engine wiring harness
-Flywheel
-Harmonic balancer
-Motor mounts (I know they have to be moved up. I have plenty of clearance)
-Water pump/ Power steering pump
-Thermostat housing
-Exhaust risers
-Bell housing
-Engine sensors (like temp.oil sensors
-Coil (I assume the 4.3 and 5.7 coils are the same)
-Y-pipe
-Anything I am missing?

 

[Bondo]

Re: 4.3 VS. 5.7 Accessories, Distributors, Motor Mounts, etc.???

I have searched quite a bit and have not came up with too many specifics on the swap.

I have the thunderbolt iv ignition. The engine is a 94 4.3 LX.

Can I reuse the following items?:

-Engine wiring harness - Nope, it'll be short -
-Flywheel - Nope, different balance -
-Harmonic balancer -Ditto, different balance -
-Motor mounts (I know they have to be moved up. I have plenty of clearance) -sure -
-Water pump/ Power steering pump - sure -
-Thermostat housing - should be Ok -
-Exhaust risers - Possibly -
-Bell housing - Flywheel cover,..?? Yes -
-Engine sensors (like temp.oil sensors - Probably -
-Coil (I assume the 4.3 and 5.7 coils are the same) - yes -
-Y-pipe - maybe donno what yer startin' with -
-Anything I am missing? - No doubt -

Ayuh,... If the 4.3l has 1 piece exhaust the y-pipe is probably different...

 

[jserr68594]

Re: 4.3 VS. 5.7 Accessories, Distributors, Motor Mounts, etc.???

Thank you sir!