lane 10 Report post Posted June 17, 2012 Had a 69 351w with small crack in back of the block, had a good 72 block so I put the internals of the 69 in the 72. Will this work or did I just waste my time. Thanks Quote Share this post Link to post Share on other sites
Fordrevhead 29 Report post Posted June 17, 2012 69-72 are the same deck height and use the same rebuild kit. Quote Share this post Link to post Share on other sites
lane 10 Report post Posted June 17, 2012 69-72 are the same deck height and use the same rebuild kit. Thats what I thought ,I read different somewhere and got me nervous about it. Quote Share this post Link to post Share on other sites
BuckeyeDemon 211 Report post Posted June 17, 2012 i thought the 69/70 blocks were 9.48 and the change was in 1971 to 9.503. The talk always seems to be the 69-72 blocks are the beefiest. Quote Share this post Link to post Share on other sites
stangme428 33 Report post Posted June 17, 2012 (edited) this is what i was told when building my 69 351w... 69/70 9.48 as buckeye stated. at the least you know you wont get into the valves with the pistons a little farther in the hole... should be interesting what the deck height is once they deck the block. i thought the 69/70 blocks were 9.48 and the change was in 1971 to 9.503. The talk always seems to be the 69-72 blocks are the beefiest. Edited June 17, 2012 by stangme428 Quote Share this post Link to post Share on other sites
lane 10 Report post Posted June 17, 2012 i thought the 69/70 blocks were 9.48 and the change was in 1971 to 9.503. The talk always seems to be the 69-72 blocks are the beefiest. Thats the same thing I read about the deck heights, should I tear it back down and wait on a 69 block? Quote Share this post Link to post Share on other sites
stangme428 33 Report post Posted June 17, 2012 Thats the same thing I read about the deck heights, should I tear it back down and wait on a 69 block? well ... talking to an engine builder when my motor was on the dyno.. they had made more power with recent engine builds with the piston slightly in the block rather than at the very top ... which i thought was contrary to a normal build.... you may want to do some research in some of the racing mags and websites .. im not an engine builder but it did surprise me when he stated that... it may be that with head technology what it is now, ring sealing etc .. who knows. so how far in the block are your pistons from the deck? Quote Share this post Link to post Share on other sites
BuckeyeDemon 211 Report post Posted June 17, 2012 just means your pistons man be down in the hole a little bit. did you measure how for down they are? blocks, machining, rods, pistons all have variation so how far down they really are is a question mark. it may drop your compression a little bit. you could have your block decked. from what i understand, they aren't very square from the factory and could probably use some cleanup. mine ended up getting .007" removed to square it up. i'm not sure how much is safe to remove. you could go for another piston or you could just leave it alone... Quote Share this post Link to post Share on other sites
BuckeyeDemon 211 Report post Posted June 17, 2012 well ... talking to an engine builder when my motor was on the dyno.. they had made more power with recent engine builds with the piston slightly in the block rather than at the very top ... which i thought was contrary to a normal build.... eek. i want to say mine are on the order of .010' out! i've never hear that it's better to be below. i wonder what the setups were. Quote Share this post Link to post Share on other sites
stangme428 33 Report post Posted June 17, 2012 eek. i want to say mine are on the order of .010' out! i've never hear that it's better to be below. i wonder what the setups were. yup i know.... dunno.. i was surprised also... dont forget to get your intake checked out it may need some cleanup to fit the new deck and heads due to material removed.. Quote Share this post Link to post Share on other sites
lane 10 Report post Posted June 17, 2012 Ive got the heads already bolted down to the block engine is put together ready to go, but I dont remember seeing the pistons sitting low into the cylinders. Guess I could run it and see what happens:confused1: Quote Share this post Link to post Share on other sites
Fordrevhead 29 Report post Posted June 17, 2012 Hmmm, better too low than too high! I better consult another sm block book! Sorry if I was mistaken. I know for sure a lot changed in 73, I rebuilt a 74 once in a F100. Quote Share this post Link to post Share on other sites
lane 10 Report post Posted June 17, 2012 Hmmm, better too low than too high! I better consult another sm block book! Sorry if I was mistaken. I know for sure a lot changed in 73, I rebuilt a 74 once in a F100. No problem, Thanks to everybody trying to help. Quote Share this post Link to post Share on other sites
1969 Mach1 14 Report post Posted June 18, 2012 I am fairly certain BuckeyeDemon is correct with the deck heights. 1969 and 1970 are 9.480", and 1971 and newer are 9.503". I went through this several years when looking for forged off-the-shelf pistons with the correct compression height for a 1969 351w block. Quote Share this post Link to post Share on other sites
Lemon Owner 11 Report post Posted June 19, 2012 Buckeye is correct about the slightly lower deck height with my recent 69 351w engine rebuild. Had to machine down the later model pistons to fit the block. Quote Share this post Link to post Share on other sites
Burn 14 Report post Posted June 19, 2012 The 1971 351w I built last year had a deck height of 9.503". Your '72 should be the same height. I ended up zero decking my block to my pistons and had .020 milled off. I don't think you'll have any issues running the '69 internals in the '72. Compression will be lower and you'll lose a little bit of power...I doubt you'll notice. Quote Share this post Link to post Share on other sites
lane 10 Report post Posted June 21, 2012 Thanks for everybodys help I think Im going to run the engine and see if I can live with it like it is. Im not trying to biuld a race car so I might just leave it alone, still kinda bothers me though. Quote Share this post Link to post Share on other sites
