motor work..

[Kid Racer]

hey guys what does it take too put a 400sbc carnk into a 350sbc..does the 350 block have to be cut and all so the 400 crank ill fit in it or will it juss fit in there....

[j0n]

you'll need an adaptor

[Kid Racer]

jon what u mean by an adaptor

[johnjzjz]

some 350 blocks with a left or right core shift will need work on the pan rail -
if you do your own work you will have to check the rod bolts as the motor is turned in a circle -- the distance between the outer edge of the rod bolt ( nut ) and the block / at the pan rail .060 min -- also in an extreem case of core shift -- the rod bolt ( bolt top outer edge ) can hit the cam lobe of course its the 4 and 6 you need to really look at and its not easy to see -- but those for the most part are extreem cases -- but only way to know for sure is to check -- being very carefull and looking at it all will save you from doing it over -- $$$$$$$$ - jz

PS : the hole the cam goes into has an edge all the way around it == first see if the edge around the hole for the cam is centered / to the cam hole -- Thats i quick way to tell if block has shift in it -- IF you do not get what i am refering to i will photo and post up in a day or so we just got caught up today in my shop and now i have some time for things, so i can do for you if you need -- jz

[Kid Racer]

yes if u could get some photos for me...thank..i am doing most of the work my self...i am trying too wait and see if i get this block from my friend cause if i dont then i have one but it needs to go to the shop and be done and all and if that is the case then ill juss have them go ahead and make it for a 400 crank...but if not then ill be doing the work my self..like i said it all dapends on if i get this other motor or not....

[WildBillyT]

yes if u could get some photos for me...thank..i am doing most of the work my self...i am trying too wait and see if i get this block from my friend cause if i dont then i have one but it needs to go to the shop and be done and all and if that is the case then ill juss have them go ahead and make it for a 400 crank...but if not then ill be doing the work my self..like i said it all dapends on if i get this other motor or not....

Remember that a stock 400 was externally balanced...

[V]

i typed this in the mornign but ran out quick and never posted it...so here it is now, lol.

first off, you need to make sure the crank and motor match up, as far as being a 1 piece rear main seal, or 2 piece. Obvioulsy a 70s 400 crank wont fit an 87+ block. Also, youd need an externally balanced dampener, if the crank isnt aftermarket and setup for int. balanced. stock 400s are ext. Same thing with the flywheel. if u ever want a T5 setup behind the motor, finding a 153t ext. balanced flywheel for a pre 87 motor is practically impossible. and like john said, some areas of the block may need to be clearenced. You may also want to look into aftermarket stroker cranks designed for 350 blocks, and not a true oem 400 crank.

[Kid Racer]

well i have found a 383 kit for a 350 block but i juss wnated too know if i would still need to have the block worked in order to use this kit and all

[johnjzjz]

well i have found a 383 kit for a 350 block but i juss wnated too know if i would still need to have the block worked in order to use this kit and all

part of the job is the checking -- if your not prepaired to do it all - than dont and give it to a shop -- its cheaper in the long run -- specially when you will have to know what too look for -- some of thre guys here are very good and i am sure you can get one of them to help you out -- its really not a novis kind of thing -- jz

[Slow Z]

Aside from block clearances lets not forget that an actual 400 crank will not fit into a 350 block at all unless the main journals are ground.... and with the cost of cast steel aftermarket "383" cranks being so cheap who in their right mind would use an old 400 crank for their 383 build?

[NJSPEEDER]

slow z is right. you can get complete bottom end kits with the correct pistons, bearings, connecting rods, crank, and some even have balancer and flexplate included for a very good price.

[Jared1970Chevelle]

slow z is 100% correct.... look around stroker cranks are pretty cheap now...

[Blackwizard222]

externally balanced, flexplate and balancer. Clearancing the block is the other issue.

[NJSPEEDER]

you can also get stroker kits that use common 350/305 balancers and flexplates and stuff. they cost the same as the 400 crank kits, you just get to save some coin on the other stuff for the motor.