Author Topic: 350 to 454  (Read 12075 times)

Offline weebo74

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350 to 454
« on: October 12, 2009, 08:04:59 PM »
hello there i have a 79 k10 with a t350 trany it had a 350 in the truck but it took a dump on me and i want to go with a 454 what all do ineed for the swap any help would be nice thanks

Offline dumbucket1

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Re: 350 to 454
« Reply #1 on: October 13, 2009, 09:17:06 AM »
You will need your exhaust adapted and possibly a ps pump. The rest is pretty much plug and play.
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Offline beastie_3

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Re: 350 to 454
« Reply #2 on: October 13, 2009, 03:21:16 PM »
Will the transmission bolt right up?

Offline Captkaos

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Re: 350 to 454
« Reply #3 on: October 13, 2009, 04:58:22 PM »
the transmission will bolt up, may not last long unless it has been rebuilt or you plan on babying it.

Offline weebo74

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Re: 350 to 454
« Reply #4 on: October 13, 2009, 06:03:47 PM »
thanks for all the info guys and yes i plan  rebuilting the trany i just did not know if the t350 would bolt up the the bb or if i had to replace the bellhousing

Offline Engineer

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Re: 350 to 454
« Reply #5 on: October 13, 2009, 07:59:39 PM »
You will need a 454 flexplate (flywheel). The 454 is externally balanced. The 350 is not. It is internally balanced, so do not attempt to interchange the flywheel/flexplate between these engines.

How complete is your 454? The alternator, and PS pump use different brackets/braces. You can use your 350 water pump pulley, and crankshaft pulley, but the 454 pulleys are a different part number just for reference's sake. If you have a 454 crankshaft pulley you should use it because of the way it centers on the harmonic balancer. This is assuming that both engines are using the later model 1968~1987 "long" water pump, and before the 1988+ reverse rotation water pump.

Also, the engine mount "clam shells" (all steel engine side mount) off of the 350 will work with the 454. However, again, the 454 uses a different part number, and there is a slight difference in the parts. You should use the 454 parts here as well if you have them.

You are also going to want the 454's 7 blade clutch fan, and 4-row radiator as well.

I have done a ton of SB to BB swaps in 73~87 Chevy trucks, and it is pretty simple, almost a perfect drop in installation. But having done a few I have realized that you are better off using the BB specific parts even when the SB parts will work.

I can post all of the 454 component's OE GM part numbers if you would like, most parts are still available from GM. Good luck with your swap.  :)
« Last Edit: October 13, 2009, 08:13:16 PM by Engineer »
2002 Chevy 2500HD 4x4 8.1/ZF6sp RC/LB
2001 Chevy 2500HD 4x4 6.0/4L85E EC/SB
1997 Chevy Blazer 4x4
1994 Chevy K-2500 4x4 C6P 5.7/4L80E
1979 Chevy K-30 4x4 4sp 4.10
1977 Chevy K-30 4x4 4sp 4.10 454

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Offline malibu795

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Re: 350 to 454
« Reply #6 on: October 13, 2009, 08:21:59 PM »
You will need a 454 flexplate (flywheel). The 454 is externally balanced. The 350 is not internally balanced, so do not interchange the flywheel between these engines.
correct... they do run the same bolt pattern on the crankshaft up... mean if you got hen 454 internally balanced you ccould use you 350SBC stuff... this only aplies to then flexplate/flywheel
How complete is your 454? The alternator, and PS pump use different brackets/braces. You can use your 350 water pump pulley, and crankshaft pulley, but the 454 pulleys are a different part number just for reference's sake. If you have a 454 crankshaft pulley you should use it because of the way it centers on the harmonic balancer. This is assuming that both engines are using the later model 1968~1987 "long" water pump, and before the 1988+ reverse rotation water pump.

Also, the engine mount "clam shells" (all steel engine side mount) off of the 350 will work with the 454. However, again, the 454 uses a different part number, and there is a slight difference in the parts. You should use the 454 parts here as well if you have them.
there are also at least 2 different hieghts of the female mounts.... you have room for either or... just make sure they are the same
You are also going to want the 454's 7 blade clutch fan, and 4-row radiator as well.
IMO i ditched the OEM steel fans.. i picked up a 19" flex a light http://www.summitracing.com/parts/FLX-5719/ iff your dd proble go electic fan with shroud.. (00-10 1/2 ran dual electric fans on a 31x19 rad) or a thremal cltuch with over drive water pump.. and 19" fan the thremal clutch had problem cooling my BBC but it is in a malib wagon and small space and water pump to crank is 1:1
I have done a ton of SB to BB swaps in 73~87 Chevy trucks, and it is pretty simple, almost a perfect drop in installation. But having done a few I have realized that you are better off using the BB specific parts even when the SB parts will work.

I can post all of the 454 component's OE GM part numbers if you would like, most parts are still available from GM. Good luck with your swap.  :)

a mild built th400(alto brown clutchs adn 34 sprag intermeidate clutch) will handle more power then a modest built 350. with 34 sprag clutch and alto red clutches.
TC are interchange able.. i would spend littel more on then TC with a BBC doing in work to the BBC? cam? intake?
what gears/tire are you running?

fan part number 1619P flex-a-light
« Last Edit: October 13, 2009, 08:27:08 PM by malibu795 »
adam wildman
75 K25 383/400
79 malibu 454/T56 305rwhp/432rwtq 15.6@92.8mph
02 2500HD D-max/allison best time 13.77 @ 99mph 463rwhp/930rwtq