402 Big Block in 72
#1
402 Big Block in 72
Can anyone tell me if the Hi Performance pass 402 BBC is a good motor to rebuild and put in a 72. it currently has a number matching SBC in it that I want to put in the back of the garage and drop a big block into. I know I need to buy new accessories brackets and possibly some radiator changes. ( some say you can use the existing). I have a 4 speed Muncie and no air. am I simplifying this too much?
the block is Casting number 3999290 Hi Perf pass .And Heads 6272292
john
the block is Casting number 3999290 Hi Perf pass .And Heads 6272292
john
#2
Instructor
In your case building another SB might be a better choice since it's only 402 cubes and you are already set up for one. I like the baby rats but probably not cost effective for the power levels achievable. A similar built SB 400 isn't much behind a 402 BB in power levels when using stock heads.
#3
Race Director
Go with a big small block.
a 406 isn't going to be cost prohibitive, going to 427 like i did adds a lot more $$ because of the alfter market block and 2.08" alum heads and custom crank.
a 406, with mildly ported stock heads will generate the same power as a 402,and be about 150 lb lighter,and it will drop right in, no need to change springs, etc.
A hyd roller cam in the 230/236 @.050 dur range and ~ 550" lift, or so, will be very streetable in that size motor with even 9:1 CR. higher CR will need a little different cam.
Doug
a 406 isn't going to be cost prohibitive, going to 427 like i did adds a lot more $$ because of the alfter market block and 2.08" alum heads and custom crank.
a 406, with mildly ported stock heads will generate the same power as a 402,and be about 150 lb lighter,and it will drop right in, no need to change springs, etc.
A hyd roller cam in the 230/236 @.050 dur range and ~ 550" lift, or so, will be very streetable in that size motor with even 9:1 CR. higher CR will need a little different cam.
Doug
#4
Is it best to just rebuild the SBC in it? I have a spoken to a local machine shop to put flat top pistons, a 3863151 cam, rebuild the Q/Jet and distributor, some headers and 2.5" pipes and it will be much better than the 200 HP dog she is!
thoughts
Not sure what to do! re-build or drop another SBC/BBC
john
thoughts
Not sure what to do! re-build or drop another SBC/BBC
john
Last edited by Bowmajv; 11-04-2013 at 05:22 PM.
#5
Burning Brakes
Member Since: Sep 2012
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you can do a 383 sbc for less then a 400 sbc ,the 400 sbc are becoming hard to find .check out competition products for 383 short blocks and heads.or consider a 396 sbc ,with a 3.875 crank in a bored 350 block.
#6
Instructor
Converting to BB from scratch gets expensive once you start buying brackets and so on. I'd build a 383, way cheaper than in the past and will run awesome built correctly.
#7
Race Director
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2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
If you're going to go big block...go BIG big block. Don't bother with the 402.
JIM
JIM