I have been serching and reading a lot of info on the strength of the 351 block. I know that the 69 & 70 block have a 9.480 deck height and are the strongest and the 71-74 blocks have the 9.5 deck heigth and are stronger then anythig newer. My question is how much stronger is the 69&70 then the 71-74? Is it worth dealing with the shorter deck (maybe having to mill the pistons) and getting a 69 or 70 or should I just get a 71-74? I am planing on building a 408 for my 91 coupe that will be a street strip car that I want to see put down about 500-550hp to the wheels. Thanks for your help.
clang
I agree with stroke me! I really dont think there is a set number of HP one can handle over the other. Example some 302 blocks live fine with 500 hp some break over 250.
Thanks guys, your right any year block will probably hold up to what I want to build, but I would rather overkill in the strenght of the componets rather then build something that sould be strong enough. I like to know that if I want to beat the sh## out of it on the strip that it will not come apart. I was mainly wanting to know if anybody knows how much stronger the 69/70 blocks are then the 71-74 blocks. Thanks for your input.
the early blocks have strength because they can take a bit more detionation before they crack.
your term of ..."BEATING ON IT".. is a matter of you wanting to run the engine when it has improper spark advance or poor fuel or poor fuel delivery.
no engine is strong enough to take that kind of punishment.
other issue is that most do not STOP at their predetermined power output level...and they end up adding more cam or squirt it more and more because they have overran their original projection and then end up overstressing what they originally configured.....
then it blows up.
your term of ..."BEATING ON IT".. is a matter of you wanting to run the engine when it has improper spark advance or poor fuel or poor fuel delivery.
no engine is strong enough to take that kind of punishment.
other issue is that most do not STOP at their predetermined power output level...and they end up adding more cam or squirt it more and more because they have overran their original projection and then end up overstressing what they originally configured.....
then it blows up.
Kato, so you agree that as long as I have the proper fuel system and ignition timing that I am well with in safe limits with any 351 block at 550 rear wheel hores power? I am thinking that if it is going to cost about the same to build any year 351 then why would I not build the strongest one I could find? Any down side to building with an older block other than it is not roller ready? Thanks for any info you can give me.
being so called ..." ROLLER READY"... is a BIG MIS NOMER...!!!
because all that has to be done to use a hydraulic roller cam in a "non roller" block is to buy the linked lifters and ANY common roller camshaft..even a cam out of a 302 will work.
no need to drill and tap/thread any holes.
plus, the linked lifters are able to take more rpm and have more durability..most do not make the annoying clack ....clack...
if you happen to over revv a bunch, the linked lifters do not fall apart / EXPLODE and cause lots of other $$$$ damage.
the higher original purchase cost of the linked lifters is nothing in comparison to the long term advantages....!!!!
because all that has to be done to use a hydraulic roller cam in a "non roller" block is to buy the linked lifters and ANY common roller camshaft..even a cam out of a 302 will work.
no need to drill and tap/thread any holes.
plus, the linked lifters are able to take more rpm and have more durability..most do not make the annoying clack ....clack...
if you happen to over revv a bunch, the linked lifters do not fall apart / EXPLODE and cause lots of other $$$$ damage.
the higher original purchase cost of the linked lifters is nothing in comparison to the long term advantages....!!!!
once again,..
...are you really going to stop at the 550 horsepower level...??/
or are you going to eventually want more.?
there is no problem with "over building" the block according to STRENGTH related issues.
it just gives you more "fudge room" to add things /add power in the future,......
...are you really going to stop at the 550 horsepower level...??/
or are you going to eventually want more.?
there is no problem with "over building" the block according to STRENGTH related issues.
it just gives you more "fudge room" to add things /add power in the future,......
many / most all of the piston and rod lengths are common for the 9.480 deck height....
ability to predict the future just aint in my glass ball.
but I do know that many will say, .."I wished I built it able to take more power"..
where as,
you will never hear someone say .." I wished that I had used a weaker block"...
ability to predict the future just aint in my glass ball.
but I do know that many will say, .."I wished I built it able to take more power"..
where as,
you will never hear someone say .." I wished that I had used a weaker block"...
Thanks for all the info guys, I will probably end up getting the strongest block that I can find at a resonable price. It looks like any block will be strong enough for my goal but the 69-74 block will give me a little room to grow if I decide that 550HP is not enough. And what ever I end up with I will run the link bar lifters.
Hey guys you mention any 351W would take 550 to the wheels. I have the funds to turbo the car but not enough to turbo and get a dart block. I wanted to stay 302 but thought that if I can get a 351 W and throw and turbo and get 550+ ( 600 Max ) to the wheels id be happy. So the question is how much can the stock internals of a 94 and up 351W take?
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