Machinist or Engine expert knowledge required

[swampynthrcecort]

Alright so the second round of frankensteining came along nicely, christine is sitting at 9 inches with an SFA D44 in the front and a 79 14BFF in the rear with 40" Irok radials to tie it all together.

Currently I have the chance to obtain a 7.0L Mark IV GM Goodwrench Bare big block from a friend, my question of course is "is this the same block they used for the 7.4L 454?". I want to bore it out to 4.290 and put a 4.375in stroke crank in to churn out around 500ci but i'm not sure if this block will take a crankshaft like that. Anyone who knows? I'd greatly appreciate it.

other than that, heres some pictures of christine after her last remodeling.

 

[BadBob]

Is this a talldeck block? A 4.290 bore and a more standard (and probably cheaper) 4.25" stroke crank will net you about 490 ci. I know that that will fit pretty easily. I'm not for sure where you start running into problems with the mark IV as far as stroke length. Keep in mind that the main oil gallery is in the drivers pan rail.

 

[4X4HIGH]

I'm guessing this is a 427 block. The block shares the same 4.250" bore as the 454 but to even put a 454 4.0" stroke stock crank in that block requires clearancing so you won't get any stroker crank without extensive clearancing so i'm going to say you should pass on that idea and find a true 454 7.4L which will kindly accept a 4.250" stroke crank and make a 496 with the proper oversize bore.

 

[swampynthrcecort]

it is a tall deck, does that mean that a moderate 7.4L crank like a 4.250in will fit without any issues?

 

[beater_k20]

holy crap, if that's 9" my truck is gonna be WAY bigger than i expected.

honeslty, if you want 500 ci, and arent above swapping an engine, get a Caddy 500. BBC headers can be modified to work, and you can easily get BB power out of them, with SB weight.

 

[kwissman]

You can put a stock 4" stroke crank in the 427 block. If it is a tall deck you will need a lot of special parts to make it work. Like special pistons or rods, intake spacers or special intake, headers etc. Some 427/454 standard deck blocks will take a 4.25 stroke crank with a little clearancing or it may take more. The castings vary from block to block.

 

[swampynthrcecort]

yea, its supposedly 10" if i do the math, i had a 7in ORU Straight axle conversion in the front, and 5in lift springs w/ 2in blocks in the rear originally, then i put a 2in addaleaf up front+1in no rate blocks, and then i did 1in no rate blocks w/ the 4in ORD shackle flip over in the rear, it looks like it settled about an inch though, so i'll definatly go with 9" which is still tall as crap, i'm 6' 3" tall and the door sill is level with my crotchal region soooo... it basically just ended up being extra hilarious watching my 4'11" fiance try to jump up into it which makes it well worthwhile if nothing else.

as for everything else, thanks for the insight, i'll look into that caddy idea, i'm a little slow on the engine side though. for me suspension = piece of cake, but engine = major headache right now. the only engines i know are direct replacements and 2 stroke johnsons, i'm a noob in this area pretty hardcore. I want to build an engine so bad though i can taste it, i don't really think it gets any better than that.