Thread: 427 build up

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i did a search on 427 tall blocks, found alot of info, found some answers to questions i had, i was thinking that I'd go with a 4.375 stroke use 6.535 rods maybe have to do a small amount of grinding ,bore the block .060 over stock, (about 510 cubic inches) thats about as far as i got in planning, I plan to put this engine in an 85 4x4 lifted chevy truck 4 speed manual trans, i would like the engine to be streetable,run on pump gas and sound pretty mean (lopy idle) i have a set of 781 heads i wanted to use, just wanted to know if anything is wrong with my plan so far and what you guys thought? how much horse can i get out of it?i might do some comp. truck pulling with it.

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Sounds like a pretty good plan...but why the tall deck block? Do you already have one? The reason I ask is because then you get into having to buy some 'strange' parts because of the taller deck--intake (or use spacers), header fittment can be a problem, distributor, oil filter may not fit as well, etc...Yes, they are good for bore and stroke projects, but you get into some other difficulties quite often. If you use the 781 heads (good choice), plan on a domed type piston. They have a rather large combustion chamber, so to build a decent comp. ratio (9.5 or 10/1) you have to use a domed piston. Other than that, it's easy to build a 500 hp, 500 tq engine with a big block. It all depends on your other parts choices. Dont go crazy with the cam....I know you want a lumpy idle, so everyone knows you have something nasty in there, but it's easy to go too big, and then all your hard work will be down the drain. You will have a very lazy combo, that only wakes up after 3000 rpm's! You dont want that. Get a tighter lobe seperation angle (LSA) on the cam if you want chop up the idle a bit...108 or 107 will give you a lumpier idle, but you can still keep the duration and lift at a decent number so you wont kill your bottom end. The only thing you will give up by doing this is that your power band will be a bit smaller, but only slightly. The up side is that you will reach it quicker! Any of the cam co's will grind a custom cam for you if they dont stock something you want. John

johnny, I have a 427 tall deck block, bought it on ebay, if figured i could use an Hei distributor from a 366 tall deck (i know where a few donors are)the 366 had a highrise 4 barrel intake manifold (not spreadbore) kinda like the ones that came on the big block camaro /chevells (someone correct me if i'm wrong) if i don't use that, there are aftermarket performance tall deck intakes, other wise yes i'll have to use spacers, i don't think i'll have a problem with headers in an 85 chevy truck, oil filter will be no problem the one ton trucks came stock with a 454. i thought some where around .500(at valve)or higher for lift in the cam, 9:1 to 10:1 comp, some time down the road i want to get late sixties early seventies camaro i figured i could build the motor mild for the truck then go wild and dump it in the camaro