400 small block swap
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Joined: Dec 2002
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From: Kingsport,tn
Car: 1991 camaro RS
Engine: 305 Carb
Transmission: 700R4
400 small block swap
Ive been trying to find a 350 engine to start building to go in the RS. I was talking to a buddy the other day and he told me that he has a 400 small block completer engine that he would sell to me for 500 bucks. Think this would be a good idea? Also will this bolt up to my 700R4?
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From: Houston / The Woodlands, TX
Car: 82 ElCamino, looking for a 3rd gen
Engine: 305 TPI(427SB in progress) 730 $8D
Transmission: THM350 (Getting a 4L80E soon)
Axle/Gears: 10 Bolt w/ 2.43 gears :(
If it's a chevy 400 then go for it.
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From: Kingsport,tn
Car: 1991 camaro RS
Engine: 305 Carb
Transmission: 700R4
Yea its a chevy 400 chevy smallblock, but i have heard people say that for engines older than 88 you have to have a different flexplate.
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Joined: Jun 2001
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From: Charleston, SC
Car: 91 Camaro Vert
Engine: 02 LS1, HX40
Transmission: 2002 LS1 M6
you need a diffrent flexplate and a diffrent balancer..
if you're putting diffrent heads on it, it needs the steam holes drilled (if someone charges you more then $25 for the steam holes, you're being ripped off)
thats it. everything else bolts on like stock.
if he has a flexplate for it already, that will work with your 700r4. thankfully GM kept the converter bolt battern the same
that really doesnt add up to much, and the potential power increase is worth it.
if you're putting diffrent heads on it, it needs the steam holes drilled (if someone charges you more then $25 for the steam holes, you're being ripped off)
thats it. everything else bolts on like stock.
if he has a flexplate for it already, that will work with your 700r4. thankfully GM kept the converter bolt battern the same

that really doesnt add up to much, and the potential power increase is worth it.
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Joined: Nov 2001
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From: heartland
Car: 89rs (previous 2.8)
Engine: 406
Transmission: 700r4 (for now)
Sounds like a fair deal to me...you need the 168 tooth flexplate..everything else will be fine. The balancer is 400 specific. So make sure you get the right one , if it doesnt come with one.
If you are running headers you will most likely need a mini starter. The 400 block has a staggered bolt pattern. Some are drilled with a 3rd hole some are not...this is an area you may have some questions about...I did!
You will love the power of the 400!

If you are running headers you will most likely need a mini starter. The 400 block has a staggered bolt pattern. Some are drilled with a 3rd hole some are not...this is an area you may have some questions about...I did!
You will love the power of the 400!
Last edited by Riley's35089rs+; May 7, 2004 at 08:49 AM.
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From: Cypress,Tx
Car: 89 Camaro RS
Engine: 350 carbed now
Transmission: World Class T5
Axle/Gears: Peg Leg w/ 3.73's
You really dont need all that much for the swap, just the things that everyone else has already metnioned. Although I defenetly wouldnt just swap it in straight. Change the heads and cam. Even though its a 400 they still performed crappy stock because of smog restrictions. I also hope you dont plan on keeping this thing tbi, although it would be unique.
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From: Kingsport,tn
Car: 1991 camaro RS
Engine: 305 Carb
Transmission: 700R4
If i get this engine i will probably rebuild the whole thing, also will vortec heads work on this engine and will i be able to use my TBI with bigger injectors? Thanks for all the help!
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From: heartland
Car: 89rs (previous 2.8)
Engine: 406
Transmission: 700r4 (for now)
The vortecs will work....for the 400 I would go with a carb set-up. You will be happier, and run stronger in the top end...Ok no bashing please!
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From: Lowell, MA
Car: 89 Camaro RS
Engine: sbc 400
Transmission: th350
i had gotten a similar deal that you are. managed to drive home a 78 c10 with a sbc 400 and th350 in it for $500. went carbed though. looking forward to some vortec heads too......
i went the route of completely rebuilding it and highly recommend you get the thing checked out just to make sure there are no cracks or anything in there. there is deffinately a huge difference from the beat 305 i had to toss out....
i went the route of completely rebuilding it and highly recommend you get the thing checked out just to make sure there are no cracks or anything in there. there is deffinately a huge difference from the beat 305 i had to toss out....
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From: Evansville,IN,USA
Car: 89' T/A, 00' Firehawk
Engine: 406 Roller
Transmission: TH700R4 w/2800 stall
Axle/Gears: 3.23 Posi
Yeah, I love my 406, it's far from stock though. Everyone has mentioned just about everything I was going to. I use a LT1 starter to clear the hooker LT's. Balancer and flexplate are really the only other things. Vortec heads would be good, but what you will end up paying for them, the perfomance mods, and the intake, you could by a set of protopline heads w/ 200cc or 220cc runners, the 400's need a lot more air than a tree fifty., just depends on what your plans are for it.
Good luck.
Good luck.
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From: ready room
Car: NCC-1701-D (docked in AZ)
Engine: impulse drive
Transmission: fusion reactors
Axle/Gears: Rescued from the Borg by my crew
The two bolt 400 is better than the 4 bolt. I have a 406 with HSR. As long as you dont choke it with tpi you'll be fine with either carb or HSR or something other than tpi. Its a great motor.
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From: Staunton,illinois
Car: 1966 impala , 1998 sebring vert,1978 buick regal turbo, 1991 chevy silverado 3/4ton 4x4 lifted
Engine: 283, 2.5,3.8 turbo 350
Transmission: powerglide,auto overdrive, th350,4L80
no one else has mentioned this so i guess i will before you pay the cash for this ..is it in a vehicle where you can hear it run?? if not how long has it been sittin around ?? you may want to have the block checked for cracks any engine that sits too long is prone to cracking i had a 350 sitting in my garage that was fine when we stored it and when i sold it to the guy i told him to go get it checked out to make sure its not cracked and sure enough it had a small crack in it...and it was a complete engine heads and all still bolted up kinda weird but it happens so i gave him a different engine in return for the boat anchor i sold him the first time and now all is good and i have a good boat dock anchor if anyone is interested..LMAO......anyway it should net you some good power gains over a 305 or 350 once rebuilt your gonna love it
Last edited by THEGENERAL; May 13, 2004 at 02:20 PM.
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From: GO PACK GO
Car: 83Z28 HO
Engine: Magnacharged Dart Little M 408
Transmission: G Force 5 speed
Axle/Gears: Moser 9" w/Detroit Trutrac
And if you're putting a hefty cam in it - GET A HIGH TORQUE STARTER. I found that out the hard way. Now I have to wait till I get mine.....
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