I'm leaning towards the amsoil because have heard nothing but great things bout it. Or if anybody has any other oil recommendations. And should I go synthetic or regular. It's a 454 in a jet.

I hav been using and selling Amsoil products for almost 20 years.....

I have yet to see anyone say their products don't work...

The one issue I have with Amsoil is the vast product line, they offer IMHO too many products, so it is really necessary to school yourself on what your needs are...

Let me know if you have any questions, I will do my best to answer them....

GT

What weight oil should I use. It's just a very mildly built 454. I was thinkin 20w50. What's your input. GT you said your a dealer for amsoil, you also said they have a very extensive selection. If you could give me your input on which one or ones I should be looking at it would be greatly appreciated. And synthetic or regular. The motor has about 50-70 hours on it

Unfortunately it depends on how the engine was machined, the clearances of the machine work ultimately determine the oil, as does operating temps of the oil and others...

Who built the engine?

GT

Unfortunately I know very little about the engine. My 455 olds smoked because of the infamous oiling problems. And twas cheaper to buy another engine. So I picked up this 454 out of a guys jet boat. I know the compression was around 130 in all cylinders. Has edelbrock performer intake and 750 holley. Dunno if any of this helps but it's what I do know. Sorry

Since you have no idea how it is built, here is the smart money...  http://www.amsoil.com/storefront/rd30.aspx

I really hate making recommendations because of the vast array of opinions out there... 

You could also get something like a 0W-40, it covers a wide range of temperatures and offers the best protection, some will argue the polymers can cause issue, but it does not sound like you are going to run the thing balls out to Catalina...

Let me know if I can get you a data sheet...

GT

And I can just put synthetic in with no worries right?

What do you mean by that?

Really, the only negative to synthetics (if you can call it a negative) are, you should really stick to the same oil if you can and there have been some cases where the engine will develop a very short time seal leak either at the front cover or the rear main (some cases both) but it is rare and it normally goes away fairly soon....

My motor home did this (very well built 468 cu.in. Chevy) as did my moms IROC Camaro. Both stopped leaking within 500 miles...

Otherwise, I don't know what worries you would have with going synthetic. It's not snake oil, it is proven technology...

GT

What I meant was the motor previously ran on 20w50 regular and I was wondering if you can just switch with no negative effects on the motor.

IMHO if it ran on 20W-50 before, you really need to use the information on how it ran as far as oil pressure and whatnot...

The switching from dino to synthetic doesn't bother me much...

GT