Will this swap work?

[mwojoaa96]

Sorry to beat an already well beaten horse. Just looking to peer review my facts on this swap to make sure I got all my ducks in a row. Let me know if you see any issues.

I have a 1995 c1500 auto blown 4.3 that is coming out.

I have a tired donor 1995 c1500 auto 5.7 for parts but not using this motor as it’s got 300k on it. Just scavenging things I may need for the swap, ecu, sensor plugs ect. (Harness is no good)
Buddy has a low mile 350 out of a G30 Camper low miles.

I’m under the impression that the g30 350 is the same block and heads just minus the intake and the accessories obviously being different.

here’s my process I need fact checked
>gonna swap all my accessories off the 4.3 onto the g30 motor and whichever flex plate fits
>intake and tbi unit off the parts 5.7 parts truck or just the injectors and onto the g30 motor
>already swapped in a trans with the v8 clutch packs but opting to use the 4.3 high stall converter
>swap to the 95 5.7 parts truck ecu
>install correct motor mounts, radiator and shroud, and headers
>drop in the dressed up g30 motor
>using 4.3 harness and changing the distributor and the sensors that don’t match(the donor 5.7 harness was cut up by the seller while parting out)
>bolt everything up, electrical, fluids ect
>good to go?

Only things I’m unsure of is fuel pressures, have a brand new 4.3 pump and filter and lines on the truck.

Will I need to change my camshaft off the g30 motor. I have the one in the 95 5.7 and also a mild comp cam for the potbelly pig sound on standby unsure of what to do.

Is the timing and firing order different?

Should I get e-fans or just run the clutch fan from the 5.7?!

I am aware of exhaust, brakes, rear end. Mainly concerned the swap itself.

Thanks and let me know what you would do and if everything seems good!

 

[docstoy]

What year G van ? Small block firing order same . If 4.3 is TBI fuel pressure same ,as far as I know, electric fans will need something to control them and electrical may have to be upgraded for increase in load and not sure when fans turn on what that will do to fuel trim that won't be in programming of your '95 pcm. Hope it helps

 

[454cid]

I would use a mechanical clutch fan. Getting an electric fan to work well, is a project in itself, from what I've read over the years.

 

[Schurkey]

As said--describe this "G30".

What fuel system do you have on the 4.3L? Buddy of mine has what looks like a Vortec spider injection on his '94 S10 4.3, but it's batch-fire instead of sequential like the more-common "OBD2" spider.

Stay with the fan clutch.

 

[mwojoaa96]

What year G van ? Small block firing order same . If 4.3 is TBI fuel pressure same ,as far as I know, electric fans will need something to control them and electrical may have to be upgraded for increase in load and not sure when fans turn on what that will do to fuel trim that won't be in programming of your '95 pcm. Hope it helps

Year is 1984.
Thank you I probably will just stay with the stock fan then.

As said--describe this "G30".

What fuel system do you have on the 4.3L? Buddy of mine has what looks like a Vortec spider injection on his '94 S10 4.3, but it's batch-fire instead of sequential like the more-common "OBD2" spider.

Stay with the fan clutch.

The g30 is a 1984, I’m picking it up Friday. It’s already pulled, believe it’s carbed and uses the v style serpentine accessories.

My 4.3 has the standard pre vortec tbi injection. No fuel spider. OBD1 with a two injector tbi unit on top. “Fake vortec” valve covers

Hope that helps

 

[Schurkey]

1984? Should be a two-piece rear main seal engine.

Therefore, you'll need the flexplate from that engine, because the flexplate from a one-piece rear main engine won't fit.

Depending on the flexplate used, you may/may not need to keep the same starter motor that's on that engine.

IF (big IF) you start mixing-and-matching the torsional damper/timing cover, be sure the damper timing mark aligns with the timing indicator.

The TBI intake manifold will need the two middle bolt-holes on each side elongated to fit the '84 cylinder heads; and you'll need the tapered washers to go along with the revised bolt angle.

 

[Scooterwrench]

'84 two piece is also internally balanced so keep that in mind when choosing a flex plate. Your '95 engine should have the 168 tooth ring gear so as long as you buy the big flexplate(168T) your starter will fit. Make sure the flexplate has the same bolt circle as your torque converter. Water pump will have to be changed for a counter rotating pump. Pulleys and brackets should bolt right on the '84. As Shurkey mentioned you will have to modify your intake for the early heads or freshen up your '95 heads and bolt them onto the '84 block but only if it has dished pistons. Use your '95 dist. and secondary ignition. Basically the "smart" part of the engine is the top end,only electronic device in the block is the knock sensor. I won't swear to it but I think the motor mount pads are the same for V6 and V8.

 

[Schurkey]

The g30 is a 1984... ...believe it’s carbed and uses the v style serpentine accessories.

I don't know what a "v style serpentine" is. If it's got V-belts it's not serpentine. If it's serpentine, it's not V-belts.

Serpentine almost always spins the water pump in "reverse" rotation compared to V-belts, so as said, the water pump will need to match the accessory drive.

Make sure the flexplate has the same bolt circle as your torque converter.

Yes.

Water pump will have to be changed for a counter rotating pump.

Whatever matches the accessory drive, and IS NOT a "96-newer Vortec" water pump that has no coolant bypass passage.

or freshen up your '95 heads and bolt them onto the '84 block but only if it has dished pistons.

Flat-tops will be fine. GM used flat-tops on TBI Caprices in '91--'92-ish. I used a Caprice service-replacement crate engine in my '88 K1500 for eighteen years.

Use your '95 dist. and secondary ignition. Basically the "smart" part of the engine is the top end,only electronic device in the block is the knock sensor.

Yup. Probably want to replace the heater-hose quick-connector with the Dorman unit. Also the TBI base gasket, EGR gasket, and so forth.

I won't swear to it but I think the motor mount pads are the same for V6 and V8.

I don't know about the pads, but the mount brackets are very different.

 

[Scooterwrench]

Flat-tops will be fine. GM used flat-tops on TBI Caprices in '91--'92-ish. I used a Caprice service-replacement crate engine in my '88 K1500 for eighteen years.

Won't that run the compression up to the point it will need high octane fuel only?

 

[Schurkey]

Caprice flat-tops raised the compression ratio from 9.2 to about 9.6. Never had a detonation problem, never filled with anything but 87 octane.