Thread: 427 tall deck

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I just purchased a 1978 427 tall deck block off ebay. I wanted to build a big mountain motor, close to 500 cubic in or a little over, but i read in a book the most stroke the block can take is 4.125 with a little griding on the block any thing over that stroke and you have to do some serious grinding on the block , i guess i just want to know how big i can go (cubic inches) without doing alot of grinding?

thanks

a 4.250 .4375 4.500 stroke. look thru some of the old post on the tall decks i have posted on them many times the rods have much to do with how much you grind out to you could get any were from a 496 to 541.2 the 541.2 would be max bore .a525.8 would be a 060 over bore and a4.500 stroke some of them blocks have more room then the very old 427 and cut out in the crank case for more stroke like a 454 i had a older 427 tall deck that could have gone to 4.500 that would of been a572.6 so if it has thick walls and you short fill it you may get to a4.437 bore and a 4.500 stroke would be a 556.8 but that may be pushing your luck so a0.100 over or a.060 over would be good

Hope ya did'nt get a 366 tall block, have seen a few passed off as 427's

Originally Posted by viking

Hope ya did'nt get a 366 tall block, have seen a few passed off as 427's

Lots of em in buses and dump trucks.

Originally Posted by viking

Hope ya did'nt get a 366 tall block, have seen a few passed off as 427's

who would do what on e-bay ??a 366 would make a good but very big paper weight or boat anchor

i checked and triple checked the numbers went and looked at it and every was good no question in my mind its a 427t, and i don't think you can bore a 366 out to 4.250

Originally Posted by chevy427tall

i checked and triple checked the numbers went and looked at it and every was good no question in my mind its a 427t, and i don't think you can bore a 366 out to 4.250

If it's a 4.250 bore not only is it a 427 it's a virgin bore, cool

Originally Posted by chevy427tall

i checked and triple checked the numbers went and looked at it and every was good no question in my mind its a 427t, and i don't think you can bore a 366 out to 4.250

no you can not. that is why a 366 make fine boat anchors. on what is a big block worth what size is the bore and size on the crank. burn mains or rods and so on. so it hard to say i will not pay much for them if they need alot of work best thing is to put the engine on E-bay they seam to go for more than i would pay for one

i looked at alot of 427t blocks(on ebay) and most of them ranged from 250 500 bucks for just the block, this one guy had one up for auction, the block was rusty so were the bores it hadn't been checked over by a machine shop, starting bid was 350, i waited untill the auction ends (no one bid on it) asked him if he would take 200 for it and he said i was crazy and that it was at least worth 350, told me i was a cheapskate, the block i bought was a virgin bore and had been hot tanked but not checked for cracks, i bought it under the conditions that if the block was found to have cracks i'd get my moneyback, it didn't have any cracks

still a big block. not totally a worthless cause

what did u pay for the 427 on ebay--reason i ask i have a 454 complete that i go to sell i would like some idea on what to ask for it
thanks

siw234 the big block engines seem to run from 250 (what i paid for the 427 block) to 800 for a rebuilder depends on how complete it is, and what heads are on it, two bolt mains or four bolt ect.

i do alot of big blocks i did at one time did get some new gm tall decks for 500 new they did not need any thing. sold one and made a 525.8 from the one i did not sell that was a good price maybe i should pickup more .but know every one wants 572-632

You guys and your tall deck blocks!!!!!!!!!! Jeeez!!!!!!!!! They're ALL paper weights to me

Hi Pat!! How's it going??