I've got a couple complete tall deck 427's I salvaged from 70's trucks we'd had for years. Both ran fine but other parts of the trucks made them not worth fixing. I've read these motors have steel cranks, 4 bolt mains, and pretty good rods, so I'm wondering if one of them would make a good basis for a sorta mild street driven blower motor. We ran a lot of 71 series Detroits in heavy equipment so there's also half a dozen or so good 6-71 blowers around the shop that I could convert for gas use. I own a machine shop with a wide range of cnc and manual equipment, so if I did this I'd make my own blower drive parts for the most part as a side project. Do you have to use tall deck specific manifolds or can you adapt standard BBC manifolds via spacers? If so, are spacers commercially available or do they have to be custom made? As I understand it, the tall deck blocks have the same rod length as the other BBC's and its the piston pin location that makes up the difference in deck height. Correct? Are replacement pistons killer expensive, or about the same price range as other big block pistons? I'd ***ume truck heads ain't exactly performance items, but would they be p***able if a blower is shoving air thru them? Input or advice? Send these boat anchors to the s**** yard? Whatever. Thanks in advance.
An inexpensive tall deck is not practial. The piston gets its extra .400" from an extra compression ring also lots of weight. Spacers are all over Ebay but mostly for rectangle port heads. Plus you will need a distrib with a slip collar or modify your chosen intake for the short stock distrib. A blower win't really care abot the small intake valve. But truck heads use heavy rotators and short springs. $$$$$ to get the heads to mediocre.. +/400 rods will allow use of regular pistons If you can do must of the machining a lot of cash can be saved, but most of the required machine work has to be done on automotive equipment that is much different fron non auto machins.. I usually tell my customers to sell the tall deck to a drag racer and use the money to build a good short deck engine..
Thanks for the detailed info Bob. Sounds like a free motor could get real expensive, real fast Any idea what the stock bore 427s are worth to drag racers?
Order the spacer, get an intake and dist. and install. Your car is now big block powered. It will be a torquey ride for cheap. I bet it will run in the 8's
Used to be the tall decks were useful for building stroker motors, but not so much these days with all the different rods and pistons you can buy, as well as the aftermarket blocks, etc. The pickup truck 454s are nice motors for building a mild performance big block. If you don't get crazy with boost, you can get by with the cast crank and 2 bolt mains. If you want to have fun, get a pickup truck short deck 454 block from around 1990, it will have 4 bolt mains. Put in the 427 crank, some flat top pistons, open chamber rectangle port heads, and then stick the blower on it. That's what I'm doing with my altered wheelbase Chevy II.
Thanks for mentioning that Jim. We've got a mid 80's C30 out in the field behind the shop that's got a 454 crate motor in it that we put in around 90 or 91 when the original lost the top of a piston and the rod made a couple p***es around and thru the block. Old truck isn't worth much due to rust issues now but the motor does have less than 50K miles on it so that might be a good way to go. I'm not looking for 800hp or anything like that. Just want to have me a blower motor at some point. I've built probably a dozen 6-71s over the years, but somehow its just not exciting to hang the blower back on the side of one of those critters
we run tall deck blocks and use Indy intake no spacers they need to be port matched little field 8-71 20% over
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