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454 Vortec to 8.1 Swap


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#1 Toybox

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Posted 04 February 2007 - 12:25 PM

I have a 98 454 Vortec Surburban. Engine has 60 pounds oil pressure, but is getting no oil to rockers. Been told that is common on these engines. The engine does have in excess of 100,000 miles on it. Hate to go to all the trouble of an engine swap without gaining something.
Wandered about swaping to a late model 8.1.

My burb has the 4l80E Transmission.

Will the 8.1 bolt up to the 4l80? Will my intake and electrtonics bolt up to and feed the 8.1. Will the 8.1electronics interact with my truck? Just starting to look at this and have a thousand quiestions.

Thanks

#2 95Sierra2500

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Posted 04 February 2007 - 01:04 PM

I'd recommend either rebuilding that 454 or upgrading to a base 502. The 8.1 would probably bolt in but I don't know that the electronics will work too well.
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#3 redvett

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Posted 04 February 2007 - 02:08 PM

It will bolt up like all rat motors but you will have to get the truck on a dyno and have a new set of calibrations done. With an increase of around 41 ci your going to have to have more fuel.

#4 Toybox

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Posted 04 February 2007 - 08:50 PM

I have a 98 454 Vortec Surburban. Engine has 60 pounds oil pressure, but is getting no oil to rockers. Been told that is common on these engines. The engine does have in excess of 100,000 miles on it. Hate to go to all the trouble of an engine swap without gaining something.
Wandered about swaping to a late model 8.1.

My burb has the 4l80E Transmission.

Will the 8.1 bolt up to the 4l80? Will my intake and electrtonics bolt up to and feed the 8.1. Will the 8.1electronics interact with my truck? Just starting to look at this and have a thousand quiestions.

Thanks



#5 Toybox

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Posted 04 February 2007 - 08:59 PM

Probably going to show my ignorance here, but what would be the difference in the base 5032 and the 8.1? I mess with boats a little and I have a create 502 HO and a crate 454 HO setting in the shop. What is the difference between the crate 454 HO and the Vortec? I mean besides the heads?? If I took the crate 454 HO and put Vortec heads on it, would I essentually have a 454 Vortec? If I took a 8.1 ansd stripped it down to a long block, would that be any more difficult than starting with a long block 502?

#6 redvett

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Posted 05 February 2007 - 08:17 AM

I would be concerned with compression ratio in the HO engines compaired to the stock truck engine.

#7 vortecfcar

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Posted 05 February 2007 - 10:18 AM

If I were in your shoes I would not go through the hassle of switching to a gen 7 8.1. A replacement 502 or 540 shortblock would be much simpler and just as effective. Your stock 7.4 topend would bolt to either one of these shortblocks without a hitch. You could also use a slightly bigger cam for additional giddyup if so inclined.

another option would be to use your stock block and put a new rotating assembly in it. You can make a 496/540 for about 2000 dollars in parts from a place like this http://www.cnc-motor....asp?CtgID=9045

#8 ThorsHD

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Posted 05 February 2007 - 08:35 PM

Probably going to show my ignorance here, but what would be the difference in the base 5032 and the 8.1? I mess with boats a little and I have a create 502 HO and a crate 454 HO setting in the shop. What is the difference between the crate 454 HO and the Vortec? I mean besides the heads?? If I took the crate 454 HO and put Vortec heads on it, would I essentually have a 454 Vortec? If I took a 8.1 ansd stripped it down to a long block, would that be any more difficult than starting with a long block 502?



an 8.1 is 496 ci. it is a diff block. if I remember correctly the 502 is a boared out 454. same strock, same block.

I think.





I'd go with a 502

#9 Tyler_LS1

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Posted 05 February 2007 - 09:24 PM

I would just do a performance rebuilt on the top end. once you open it up that 454 will scream.

and it would be cheaper than buying a new engine.

just a thought.
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#10 svensk

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Posted 13 February 2007 - 01:39 AM

496 is the same block as the old 454. Just like they kept the same small block used in the 350 for the 6/5.3/4.8 etc.

Seriously though I agree with the above post it would be cheaper to take it to a performance motor shop have their wizards work on it. They could probably get you 500 bhp if you wanted it.

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#11 xx_ED_xx

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Posted 17 October 2007 - 10:45 AM

8.1 496 is not the same as a 454. I have pictures if you need to see the difference. even the firing order is different. Just fix the 454

#12 genuinefine409

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Posted 17 October 2007 - 07:33 PM

The 350 is different than the new LS engines. You can get a 496 BBC to drop in(stroked 454), you go all the way up to 632 fairly easy if you want and got a little bread to spend but that would be just silly. GM used to have a drop in 502 crate motor with 500+lb/ft torque as a drop in for the 454TBI engines, they might have something that'll work with the vortec. I would sooner fix the 454, if you are looking for more grunt possibly swaping out the cam for a towing cam or something.

#13 dietzster

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Posted 30 December 2007 - 09:55 PM

I too have contemplated this swap and it still is not off the table. The 8.1 will bolt up to your tranny
the block on an 8.1 is basically the same as any other big block, but it is a tall deck big block
that is how they get so much stroke in it. It even has the same bore size as a stock 454. I was thinking about bolting 454 heads on it and using the factory 2 piece intake (off 98 vortec 454). It will work, the only thing needed are spacers from the heads to the intake to take up the space (tall deck intakes are wider than short deck intakes). And a custom tune and you should be good to go. That is what I know from the research I have done. Also the firing order is different, but you can put any big block cam in it with regular firing order and it will work, as long as its for computer controled engine

Edited by dietzster, 30 December 2007 - 10:30 PM.





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