A518 to 47RH swap

BlackSkyRacing

BlackSkyRacing

Living Under a Rock
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Mar 22, 2007
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Ok, so a friend of mine has been in the market for a 12 valve for quite some time and found a 92 that he REALLY wants... He want's to go sled pulling with it and I don't think he'll be terribly happy with the A518 and how much it's gonna slip when he hooks to the sled. I have a mildly built 47RH laying around and would like to know what all is involved in the swap? Is the 47RH longer, will the older transfer case bolt up, do I need a flex plate?

Thanks in advance guys.

BTW how does a 14mm H&R, 6x.018s, denny t fuel pin, 366 spring sound for a good start? Think with a decent turbo that it's a recipe for 400+ rwhp?
 
Flex plate, engine to trans adapter, starter and a TCM unless you just want to run OD and lockup with switch. Tcase will work, driveshafts will work. The tcase shifter will need modified. I did the swap on my 92 and it works perfect.
You won't need a 14mm head to make 400hp
 
J.Keith said:
Flex plate, engine to trans adapter, starter and a TCM unless you just want to run OD and lockup with switch. Tcase will work, driveshafts will work. The tcase shifter will need modified. I did the swap on my 92 and it works perfect.
You won't need a 14mm head to make 400hp
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His goal is actually 500rwhp(ish) , I just wanted to make sure I was on the right track since I'm more of a P-pump guy...

Crap... I totally forgot about the engine to trans adapter. Switches aren't a problem, I've actually got them in my 94 from when my PCM took a dump on me and he doesn't mind them.

Though that's quite a laundry list of parts for the swap... I think I'll try and convince him otherwise simply because he want's to be fast(ish) AND be able to hook to the sled and I just don't think the open converter is a good idea. Though I can't say I haven't had a few friend try it and do decent, I just don't want him to be disappointed. I guess the bonus of the A518 is the lack of necessity for a billet input :bang
 
I have a customer that also has a 92 that I built the A518 in and put a tight 3 disc converter in. Both trucks run the same fueling mods, same turbo and same size tires. Mine is much faster than his and gets about 4mpg better.
 
J.Keith said:
I have a customer that also has a 92 that I built the A518 in and put a tight 3 disc converter in. Both trucks run the same fueling mods, same turbo and same size tires. Mine is much faster than his and gets about 4mpg better.
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Ok so you`re saying a built A518 with a tight converter is still no match for a 47RH in mild to moderate builds? This is what I was thinking as well, I`m sure the lack of a lock-up converter is what kills it...
 
Correct. Not saying the 518 is a bad tranny, several people are going fast with them, but I'd much rather have the 47 in there.
 
J.Keith said:
Correct. Not saying the 518 is a bad tranny, several people are going fast with them, but I'd much rather have the 47 in there.
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Any ideas where to find the engine to trans adapter plate? My source doesn't want to let go of his "spare" :bang
 
when i did the swap i had to shorten my driveshaft. the tranny gets moved back about 2" because of the adapter. that also means moving the trans brace back and putting new bolt holes in the frame.
 
daithi2 said:
when i did the swap i had to shorten my driveshaft. the tranny gets moved back about 2" because of the adapter. that also means moving the trans brace back and putting new bolt holes in the frame.
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OR --

torching the frame very carefully because the mounting bolts were put in FROM THE TOP OF THE FRAME !!!
Instead of trying to lift the cab we very carefully elongated the bolt holes..Couple of times I thought we might end up holing the cab but the guy using the torch was a h@#$%#ll of a lot better at it than me ...
 
I think he'll be fine with a good converter in the 518 to start. Cole (Smokin93) had a non-lockup Spec-Rite converter in his that was holding c.700rwhp.
 
JQmile said:
I think he'll be fine with a good converter in the 518 to start. Cole (Smokin93) had a non-lockup Spec-Rite converter in his that was holding c.700rwhp.
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Considering he wants to put some distance on an 06 Duramax I think not having to deal with at least 10% power loss through slippage is worth the swap... I wouldn't be as worried if he was trying to be faster than said truck, but with 30k+ pounds behind him it's a different story.

Not to mention I already have a complete 47RH with a fresh rebuild with borg-warner clutches and a VB already lined up for $500. I'm gonna have him wait till he can afford billet input and output shafts as well as a good TC before we put it in.
 
I agree, skip the 518, wipe your rear with it and go with the 47rh. Then since he wants to sled pull with it, skip the VE and go to a high(er) rpm p-pump. I'm all for the VE pump when it comes to starting, reliability and the cool factor of making HP with the lowly VE. But for competition, don't waste your time.
 
x2 on the rpm thing. VE's are no match for a p-pumper.
 
bgilbert said:
I agree, skip the 518, wipe your rear with it and go with the 47rh. Then since he wants to sled pull with it, skip the VE and go to a high(er) rpm p-pump. I'm all for the VE pump when it comes to starting, reliability and the cool factor of making HP with the lowly VE. But for competition, don't waste your time.
Click to expand...

JQmile said:
x2 on the rpm thing. VE's are no match for a p-pumper.
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Agreed :Cheer: But for now I'm gonna do what I can with his poor little VE pump.

EDIT: Jason, clean out your PMs...
 
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suncoast told me that would have to shorten the driveshaft 1" due to the block plate for a '94 to '98 auto 12v being an inch thicker to compensate for the lockup converter as opposed to the a 518 being non lock up. so you'd have to add 1" to the front driveshaft and remove 1" from the rear drive shaft.

ps: just go with two switches for lockup and o/d, much easier. my .02
 
tennesseekid said:
suncoast told me that would have to shorten the driveshaft 1" due to the block plate for a '94 to '98 auto 12v being an inch thicker to compensate for the lockup converter as opposed to the a 518 being non lock up. so you'd have to add 1" to the front driveshaft and remove 1" from the rear drive shaft.

ps: just go with two switches for lockup and o/d, much easier. my .02
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I've dealt with lengthening and shortening drive shafts before... My 94 has the two switches already and so that was my plan for this guy's truck :Cheer:

BTW do my eyes decieve me or is that a friggin small block chrysler bell housing?!?
 
gwhammy said:
What transfer case does the 518 use?
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The one under my friend's 92 looked an awful lot like an NP205 to me... Either way it was gear to gear with a cast iron case :Cheer:

BAD1stgen said:
are the converters from a 48re the same as a 47rh..
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IIRC no, pretty sure they made some minor changes part way through the 47RE that would have prevented even a late 47RE converter from working with an RH.
 
So is the overdrive on a 518 is the same as the 47rh? I'm thinking of a motor swap down the road and would like to use the 47rh and a 205 transfer case. I've done alot of looking but can't find a solid answer if the 205 can be bolted to a rh.
I'm not sure you can get enough fuel out of the little pump to pull a locked convertor unless you are running some real steep gears. Maybe locked in 2nd but not drive.
 
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