GT40P Head Replacement

351W Torque Sequence

I’m sure one of you guys knows: what’s the spec torque lbs and sequence for the GT40 heads on the 351W?
My current project is ready to have it's engine put back together. It had a rebuild with 10-12 hours on it. Not sure if the head bolts weren’t torqued or were just stretched enough to not hold torque, but those cylinders were slam full of antifreeze when I pulled it apart and the impact didn’t even stutter pulling the head bolts.
On the bright side, rebuilding a 12 hour engine is the cleanest rebuild I’ve done.

BRKOUT1K wrote: OBTW- I work with a guy that is selling an 'older' Malibu if you know anyone in the market...I'll get the flyer and post if there is an interest.

Here's a pic of the flyer that was posted @ work! Hope it's not a forum party foul to 'advertise' for him since it is not a Nautique:)

KENO wrote: GottaSki wrote: huh, bolt holes look small, don't look opened up yet. are they? BRKOUT1K wrote: Found a pair of GT40P heads for $535 (includes shipping from Chicago)...1/2 holes w/ Brass plugs. Anything else I need to be on the lookout as far as compatibility is concerned? Hopefully just an eyeball calibration issue Gotta Ski. The above was from a post in his transmission thread

Gents,
I was able to pull one of the head bolts and confirm that it fits!   Glad you pointed it out so it will be one less thing that could potentially hold me up once we start pulling it apart...

There’s nothing that stock ratio (1.6) roller rockers would impact... theyre just a little lighter weight and less friction. Increased ratio on the other hand, would be a change similar to cam that may cause tuning issues.

Although some of you claim to be 'backyard hacks' , I can't thank you enough for all your inputs....I might have learned more on this forum than i did after 6 years of 'struggling ' to get through school...Admittedly, I had flashbacks after the 'simple stress-strain' comment Appreciate everyone's help. I know 'swapping' out these heads is probably a simple task for many of you (and I"m no pro) so it is a little more of a challenge to this ol' bus driver. Looking to make sure i've got all the i's dotted and t's crossed! Thanks again....

A little more background....I'm told this boat had some 'issues' before I bought it with the ECM and it was replaced...seems to be running well with the new or used replacement with the exception of the water leaks .and a few 'noises' that i wouldn't have honed in on.   Without all of the time I've spent trying to work out all the gremlins I probably wouldn't have heard most of 'em with the music cranked up!

You can reuse your rockers and pushrods but you should check your lifter preload. Later on if you wish you could go for roller rockers

I was hoping that I could reuse the existing ones, but am open to any ideas! I went with the GT40P's based on Keno's recommendation and am ready to listen to all advice on this project.

phatsat67 wrote: Better change the wheel lugs with every tire rotation.

Good thinking Zach

I'm gonna change my studs too, 'cause I don't want to worry about my nuts falling off

keno..... ARP does state you can reuse there head bolts if you use there moly lube and torque them to there spec but they can only do that one time after initial use. Your more then welcome to reuse head bolts as many times as you like (it’s not my engine) but is $80 really worth it??? I think not

Stress strain curves. Basic stuff.

A little light reading from ARP, you should probably read it Joe.

There might be a question about reusing bolts.................and an answer   

Funny thing....................You can have your opinion, I'll have mine and everybody else can have theirs too.

link

Give it a rest. That new bolt you just put in stretched when you torqued it down. Using stretched bolts are cutting corners! Time for a new bolt. Now the next bolt... wait a minute...

I know the difference between torque to yield and normal head bolts obviously but the fact of the matter is a standard head bolt still stretches and if reused it will not achieve the proper spec ever again. I’m not here to tell people what to do but cutting corners like that to save $80 isn’t right in my book but go ahead and do what you feel is right

Or Pete's favorite- Auto Zone . He buys all his parts for his backyard Hacker Craft there.