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Discussion Starter · #1 ·
Has anyone installed a 4.3 v6 into a tri 5 and if so give me some fee:driver:d back as I plan on doing this to my 56.
 

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There is a guy here in town with a 57 4dr that has the 4.3 and a 700R in it. He says it is a great cruiser. The install shouldn`t be any different from a V-8 install, just sit back a little farther than the V-8.
Terry
 

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I've not done this but the side mounts arent in the same place on the block as a v8 so using aftermarket v8 side mount brackets wont work without some changes/fabrication. Also dont mount it to the front original mounts it will be also be to far forward and will have oil pan - drag link interference and will require drive shaft and trans mount relocation.. If you still have a transmision in the car bolt it up to it to get the fore-aft placement then address the side or front mount location in other words the back of the engine should be in the same place as a sbc v8 install.

Regards, Robert
 

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which 4.6 ?

Bobby
is it the "z" or "W" engine ?
 

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"I've not done this but the side mounts arent in the same place on the block as a v8 so using aftermarket v8 side mount brackets wont work without some changes/fabrication."

Are you sure about that? I was under the impression that on the 4.3 V6 that is essentially 3/4 of a 350, the side mount bosses were the same location from the BACK of the block as on a 350. But that would make them different from the front.
 

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"I've not done this but the side mounts arent in the same place on the block as a v8 so using aftermarket v8 side mount brackets wont work without some changes/fabrication."

Are you sure about that? I was under the impression that on the 4.3 V6 that is essentially 3/4 of a 350, the side mount bosses were the same location from the BACK of the block as on a 350. But that would make them different from the front.

The side mount pads are shifted back because they removed the cylinders 3 and 4 from the block the mount is the same distance referenced from the front of the engine as a sbc but the distance referenced from the rear of the block is shorter than a sbc so when you just bolt it up to v8 mounts if essentially moves the place where the trans mates to the back of the v6 engine up the width of the missing cylinder.


These pictures shows what I mean

http://image.hotrod.com/f/9068766/113_0208_v6_03_z.jpg ( v6 )
http://image.superchevy.com/f/34410..._block_chevy_dormant_engine+rotate_engine.jpg (V8)

notice on both the v6 and the v8 that the bottom mounting bolt pad is lined up with the #2 main cap web so from the front the measurement is the same but from the rear the v6 is shorter

Regards, Robert
 

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typhoontx, thanks for the info. The photo shows it was virtually impossible to put them the same distance from the rear.
 

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The mounts are 4 1/2 inches farther back than the V8...
 

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Discussion Starter · #11 ·
resale

Hi Bobby , my biggest concern would be RESALE a nice trifive should have a straight 6 or a V8 . Don
not worried about resal as I'm building this to be a cruiser for me,easy on gas and not afrid to go anywhere in it. I'm almost 61 years young and plan on driving this car to my grave.:bowtier:
 

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Bobby, I think it's a combo that would be interesting to some even if it wasn't to others. It's going to have more power than any stock 265 or 235 and it will have a lot less front end weight than those too. So the car will perform and handle better than a stocker.
 

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Hey Bobby,

This company "Jags That Run" makes these mounts to install a SBC V8 for a 4.3 V6 into a Chevy Astro Van. The mounts are shown in the link below. They allow you to mount the SBC in the exact location as the 4.3 V6. They look like you can flip them side to side and mount the V6 on V8 side mounts in a Trifive. When you look for your V6 there's two versions a "Z" & a "W" code one has about 150 hp and one has about 200 hp, sorry I can remember which one's which. The main difference is one is Sequencial multi-port F.I. and the other is throttle body F.I. The Sequencial one is the best.

http://www.jagsthatrun.com/Pages/Parts_AstroVanV8_Mounts.html
 

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Hey Bobby,

This company "Jags That Run" makes these mounts to install a SBC V8 for a 4.3 V6 into a Chevy Astro Van. The mounts are shown in the link below. They allow you to mount the SBC in the exact location as the 4.3 V6. They look like you can flip them side to side and mount the V6 on V8 side mounts in a Trifive. When you look for your V6 there's two versions a "Z" & a "W" code one has about 150 hp and one has about 200 hp, sorry I can remember which one's which. The main difference is one is Sequencial multi-port F.I. and the other is throttle body F.I. The Sequencial one is the best.

http://www.jagsthatrun.com/Pages/Parts_AstroVanV8_Mounts.html

"W" is the high output and some of those will be CPI fuel injection...

Central port injection (CPI)

General Motors implemented a system called "central port injection" (CPI) or "central port fuel injection" (CPFI). It uses tubes with poppet valves from a central injector to spray fuel at each intake port rather than the central throttle-body. Pressure specifications typically mirror that of a TBI system. The two variants were CPFI from 1992 to 1995, and CSFI from 1996 and on. CPFI is a batch-fire system, in which fuel is injected to all ports simultaneously. The 1996 and later CSFI system sprays fuel sequentially.
 

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I remember in 85 working on 4.3s with Q-jets and Th-400s in 1/2 ton trucks. They ran better than the 305 two barrel junk they replaced.
 

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Don't know except its a 91 roller cam motor with 85 astro van 4 barrel carb manifold and big hei. now in a 70 chevy pick up with late model truck v8 mounts.

If memory serves that engine would most likely have had tbi injection on it orginally if it came from a car or light truck rated at 160 hp.
If your going to retain the large cap hei you may need to move the engine
fwd 1/2" to 3/4" just like a sbc in a tri five with a large cap hei to get firewall clearance in some cases.

Regards, Robert
 

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Has anyone installed a 4.3 v6 into a tri 5 and if so give me some fee:driver:d back as I plan on doing this to my 56.
I also thought that this would be a good ,easy idea,I tried it in a 57.There were too many things that needed to be changed.
Nothing about it was as easy as someone who hasnt tried it,makes it sound..
 

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Hey Bobby,

This company "Jags That Run" makes these mounts to install a SBC V8 for a 4.3 V6 into a Chevy Astro Van. The mounts are shown in the link below. They allow you to mount the SBC in the exact location as the 4.3 V6. They look like you can flip them side to side and mount the V6 on V8 side mounts in a Trifive.
http://www.jagsthatrun.com/Pages/Parts_AstroVanV8_Mounts.html
Not sure if there is room to flip the mounts to the forward position on the 4.3, I can look at one later with the adapters I've made for installing a V8 in place of a 4.3...
 

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"W" is the high output and some of those will be CPI fuel injection...

Central port injection (CPI)

General Motors implemented a system called "central port injection" (CPI) or "central port fuel injection" (CPFI). It uses tubes with poppet valves from a central injector to spray fuel at each intake port rather than the central throttle-body. Pressure specifications typically mirror that of a TBI system. The two variants were CPFI from 1992 to 1995, and CSFI from 1996 and on. CPFI is a batch-fire system, in which fuel is injected to all ports simultaneously. The 1996 and later CSFI system sprays fuel sequentially.
Thanks Dave I couldn't remember which was which. I had this one in my van, I had to replace the fuel injection unit on mine, the parts dept at my dealership had 3 units in stock at $575 each. The parts guy said they have problems with them that's why they stock so many units.

ps I now remember the "central" port FI not "sequential" port.
 
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