1979 fish Natique ,had rebuilt gen 4 installed .
got a lifter tick (1) when cold mostly all goes away in a minute or 2

I'm assuming I need to pull off the intake and check it but I'm leaving on vacation and don't feel like messing with it if it doesn't hurt anything. Raw water system using straight 40 weight oil.I took it on the water once total runtime on the rebuilt engine approximately 2 hours.. runs great with plenty of oil pressure
Opinions?

What do you mean by "rebuilt gen 4"?
A GM "gen 4" is a 6.0 liter LS based small block. There are marine versions of this motor. Is that what you mean?

A "Mark 4, or Mk IV" is a 427, 454, 502 cubic inch big block chevy.

Which are you referring to?

When you say "rebuilt", is this a marine rebuild, a brand name rebuild, a cheap automotive high volume rebuild, a local mechanic rebuild?

Is this a Bravo drive installation (flexplate and drive coupler)? A TRS drive installation (to a Velvet Drive transmission)?

The noise you describe could be anything from a lifter tick to an exhaust leak to a drive coupler rattle.

Send SPECIFICS and you'll get more useful answers.

Ok. Fish Nautique is an inboard, so it won't be a drive coupler.

Depending on your exhaust manifolds, it may or may not be easy to get your valve covers off. If you can get them off easy, you should check your lifter preload. Put a breaker bar on the crank snout and turn the motor to close each valve.. with the valve closed, try to spin the pushrod to see if any are loose. You can back off of the adjuster nut, retighten to zero clearance then go another half turn on each one.

You should also rule out external sources. Pull the belts off the crank pulley and start it up to see if the noise is still there with all external accessories out of the equation.. It is also possible to have worn distributor bushings and be getting some noise from the distributor. Broken advance springs can also have a ticking noise. Rebuilt motors are often fitted with ancient un-rebuilt distributors...

Get us better info and we can go from there

Wow,,,mcollinstn, a blast from the past!

And a very welcome one if I may say so

sorry that I didn't have enough details. It is a mark 4 454:with hydraulic lifters figured out the problem number one rocker was a little loose so now all good thank you for the advice

however 10 minutes ago I started a new thread I now have a real seal leaking on my Borg Warner Velvet drive... That's the next project as that nut is kicking my a$$

You'll need to make or borrow a torque bar for the output flange. A 1/4" thick plate with 3 holes matching the ones on the flange, with clearance for the center socket. A 1.5 foot long arm/bar welded to it to chock against the "boat" while removing and reinstalling the nut. You do not want to reuse the nylock nut. Get a new one, and torque it to 150-160 ft lbs on reassembly.

I've used a 36" pipe wrench before in a bind to hold the flange, but it will gnaw up the flange.

Thank you ,
got nut off with breaker bar and the weight of my 220 lb neighbor . Anyways now time to reassemble.
Got new nut and seal of course . I'm reading that people say put RTV on splines?
Also lock tight in-between outer seal and housing ?
I assume I will grease the shaft ?

Also .... there was no washer behind the nut and the coupling I assume it's supposed to be like that?

Thanks again
Just just realized I answered you and the other thread I apologize can't delete this

If the seal surface on the output flange needs some love, then polishing it up is always good. 600 grit paper while spinning it in a lathe or drill press works acceptably. I follow that with actual polishing compound on a buffer. The main idea is making sure that there is nothing around the seal to make the rubber lip do any "work" by flexing.

All "wet" splines benefit from sealer. No need for anything "adhesive" on the splines. Just a ring of rtv in the female splines up where the end of the shaft will rest.

I prefer a washer between heavily torqued nuts and flange. Your flange is case-hardened, so it isn't a "must".

Typically, there isn't a need to put sealer between the seal and the case but it the case bore is irregular or has scrapes,, then you should. Red or blue loctite in the bore is perfectly fine if you like that thought.

Press the seal in without disturbing the sealing area. Find a seal driver that is barely smaller than the seal. If you're an old pro, you'll have a modified punch or screwdriver in your box that you use for most seals, but a full diameter driver is best.

Once things are ready for reassembly and the seal is installed, make sure you have your torque stop/arm planned out and you know how you're gonna position it.

Then. grease the seal lips, put your ring of rtv in the female splines, grease the od of the flange snout, spin it slowly as it passes into the seal, shove it home. Put whatever washer, loctite, etc and the nut on. If you do use loctite, get it fully torqued inside of 3 minutes. Loctite starts setting up as soon as you deprive it of air. The timer doesn't start until the nut goes on, so once the flange is pushed home, you have a little time to rig up your torque stop.

Have fun.

Again thank you for the detail answer so very thorough I really really appreciate it