Please help. V6-V8 Swap

92ChevyWT · August 29, 2004

I'm hoping some of you can help me out. I have an excellent condition 1992 Chevy fullsize 2WD Work Truck. It has the 4.3L pushrod V6 and a 5 speed manual transmission. I've always wanted more power and I'd love to have a 350 installed. I'd like to have a TBI fuel injected setup or better, definetly no carb setup.

I'm wondering if this swap has been done before? I'd like to keep the 5-speed also and plan on buying a rebuilt transmission. I haven't been able to find any resources on this swap.

So far this is what I have planned. A new crate 350 (year?) matching wire harness and PCM. I'm assuming the 4.3L flywheel would work? And a high performance clutch would be needed for the extra power?

Thanks for any help, if anyone would want to chat on Yahoo messenger even my name is jke_18 on there.

Joe~

92ChevyWT · August 30, 2004

Bump.. Nobody has experience or any info on this

OUMike · August 30, 2004

I'm not really to familiar with the swap to V8 with the manual tranny. Your best bet is to do a search on the forum about this matter. I know there have been several cases with the swap using the 4L60-E autos.

If I were you, I'd try to get a Vortec 5700 from one of the 95-98 Silverados. That would probably be your best bet, as those trucks probably use the same tranny. Good luck.

MCourson · August 30, 2004

If I were you, I'd try to get a Vortec 5700 from one of the 95-98 Silverados.

If you do go that route you are going to have to deal with a lot of wiring. In 96 when they went with the Vortec they also went to OBD2. To get a vortec to work you will probably need the whole powertrain wiring harness out of the donor truck.

99-2door · August 31, 2004

If I were you, I'd try to get a Vortec 5700 from one of the 95-98 Silverados.

96-98. No Vortec 5.7L in 95.

If you were to swap in a vortec you would have to use the complete wiring.

Your easiest route, while not the most power, would be to swap in a TBI 5.7L. You can use most of the injection components from your existing engine. You wil need the v8 intake, throttle body and computer. you also have to do some mods to your instrument cluster to make the tach work with the v8. (Of course yours may not have a tach anyway). You will also need v8 motor mounts. The v6 brackets unbolt from the frame and the v8 mounts bolt directly onto the frame. There are plenty of people who have done this swap. Just do a search and you will find lots of info.

Try 47-98 board

It tends to have more info for 89-95 trucks than this forum does.

Cool Zr2 · August 31, 2004

96-98. No Vortec 5.7L in 95.

There was a limited edition 95 that had the vortecs, later part of the year but they made them, there is a red one in town, its really nice.

Get a TBI 350, wiring will plug right in, the trans will work fine, they have the same bellhousing pattern, its almost a direct swap except for exhaust.

Dont get a vortec, you would be swamped with problems, the TBI fuel system can't make the pressure, and the lines arn't rated for the pressure, the wiring would be a mess, and your dash wouldn't ever work again, you'd be crusing autometer style.

OUMike · August 31, 2004

So you guys would go with a TBI V8? I've read those didn't produce that much power. I guess a rebuild with some Edlebrock parts or something.

What about transmission? I've got 176k on my current one. Would you guys have the tranny rebuilt to handle the additional power?

What kinda tach mods would be made to accomodate for the 350cid motor?

Thanks fellas...

Cool Zr2 · August 31, 2004

So you guys would go with a TBI V8? I've read those didn't produce that much power. I guess a rebuild with some Edlebrock parts or something.

What about transmission? I've got 176k on my current one. Would you guys have the tranny rebuilt to handle the additional power?

What kinda tach mods would be made to accomodate for the 350cid motor?

Thanks fellas...

They didn't make masive power, but its got only 25 ft lbs less than the first 5.3 vortecs.

Your trans will be fine, drive it untill it snaps, then rebuild it, if you ever have to. It should last forever.

And Tach Mods?

OUMike · September 1, 2004

And Tach Mods?

I read a few places that the V8 swap makes the tach no longer read properly. Any expirences??

obbop · September 1, 2004

Likely not what yah' wanna' hear but......

Ask a chap who has attempted what ye wants to do. Pert' near universally you'll be told to sell whatcha' got and buy that which has whatcha' wants.

Less work, cheaper in the long run, and you'll likely be much happier with the end results.

Those wondrous days back in the '60s and earlier when the average Joe could yank out the engine and toss a different one in are looooong gone.

Sniff.

Cool Zr2 · September 1, 2004

And Tach Mods?

I read a few places that the V8 swap makes the tach no longer read properly. Any expirences??

yes, you need to do some dash work, its easy. Its just a matter or soldering a capacitor in I think.

OUMike · September 1, 2004

Likely not what yah' wanna' hear but......

Ask a chap who has attempted what ye wants to do. Pert' near universally you'll be told to sell whatcha' got and buy that which has whatcha' wants.

Less work, cheaper in the long run, and you'll likely be much happier with the end results.

Those wondrous days back in the '60s and earlier when the average Joe could yank out the engine and toss a different one in are looooong gone.

Sniff.

Thats fine and dandy, but when my 94' Chassis and cab are in better shape than most 99s and 00s (not to mention better lookin) I prefer to keep my old body.