Help with a stroker buildup.
Thread Starter
Instructor
Joined: Jul 2002
Posts: 245
Likes: 0
From: Raleigh NC
Help with a stroker buildup.
I bought a block recently that came with crank, pistons, rods and heads (unassembled) that was already bored out .040 over. What would I have to do to drop a crank from a 400 in there? Do I need shorter rods, and what kind of machining to I need to do to the block (if any?) If the hard part's done with I'm going to shoot myself later if it's too easy to build a stroker from this point.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Just guessing you got a 350 block? ... if so ...
forget an old 400 crank ... the machinework crank'll need to grind down main journals to fit 350 block makes it a poor choice ($) ... get a NEW aftermarket "383" crank for about $150-$200 ... same stroke. You "can" use old 400 short 5.565" rods with 3.75" stroke crank (383/400) & with the 350 pistons you have now ... otherwise you'll need different pistons to use 350 or longer rods. 350 rods are 5.7" long, those & longer require different pistons. BTW, a 40-over 350 bore (4.040") & 383/400 stroke (3.75") makes about 385 ci. Most 400/383 cranks under $400 are external balance and require a different damper & flexplate/flywheel made for a 400. 350 stuff is internal balance.
forget an old 400 crank ... the machinework crank'll need to grind down main journals to fit 350 block makes it a poor choice ($) ... get a NEW aftermarket "383" crank for about $150-$200 ... same stroke. You "can" use old 400 short 5.565" rods with 3.75" stroke crank (383/400) & with the 350 pistons you have now ... otherwise you'll need different pistons to use 350 or longer rods. 350 rods are 5.7" long, those & longer require different pistons. BTW, a 40-over 350 bore (4.040") & 383/400 stroke (3.75") makes about 385 ci. Most 400/383 cranks under $400 are external balance and require a different damper & flexplate/flywheel made for a 400. 350 stuff is internal balance.
Advanced
Joined: Jun 2004
Posts: 96
Likes: 0
From: Novelty OH
open ended
Originally Posted by Enkil
I bought a block recently that came with crank, pistons, rods and heads (unassembled) that was already bored out .040 over. What would I have to do to drop a crank from a 400 in there? Do I need shorter rods, and what kind of machining to I need to do to the block (if any?) If the hard part's done with I'm going to shoot myself later if it's too easy to build a stroker from this point.
Notably.... you probably have to clearance the oil pan rails to clear the longer throw 400 crank. Also, the shoulder of the rod and rod bolts may contact the camshaft. You need to clearance there as well.
As long as the journal sizes etc. are the same and have the right bearing clearances you should be okay. You could probably have a shop clearance it for you for under 100 bucks.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
first of all you don't use a 400 crank or rods - That was 30 years ago!
You buy a rotating stroker kit within your budget. crank/rods/pistons/rings/bearings They start at @ $800
You buy a rotating stroker kit within your budget. crank/rods/pistons/rings/bearings They start at @ $800
