Gm847

[white97z28]

the XFI 467 will work well for you....with the mods you have planned.

its on the aggressive side but not crazy

Also...upgrade the fuel pump...go with the racetronix kit now...you will thank me later.
It should be the first mod performed on a LT1 in my opinion.

Thanks...and i was gonna say something about fuel i heard that guys are always needing to upgrade there pump...are injectors a good idea to?

Also you seem pretty knowledgeable about all this...i have rebuilt motors before but never gone in really deep...especially the valvetrain...If its no trouble what are some good parts to get...? And what all parts should i get? Also should i just be smart about it and just pull my motor and put new rings, bearings, and seals in it or should i just do what i planed and just leave the motor in and just do the heads and cam for now? Thanks

[N2OfedLT1]

how many miles do you currently have.....I have seen many LT1 spin a bearing when the heads are removed from the block.

Now if you are doing cam only you should be OK....gimme till tonight and I will put a parts list together for you for the cam swap.

[white97z28]

My car has about 78-80,000 cant exactly remember its across town in storage right now...lol but another issue i might have is oil pump? will it handle the new set upp?

And thanks man for all your help!

[JoeliusZ28]

how many miles do you currently have.....I have seen many LT1 spin a bearing when the heads are removed from the block.

Now if you are doing cam only you should be OK....gimme till tonight and I will put a parts list together for you for the cam swap.

I would be a counter example to both the spun bearing and the fuel pump. Ive had my heads off and the stock fuel pump has carried me into the 12s. Ive made 20 passes since the new setup and have 95k miles now.

Not saying an upgrade isnt a good idea but I personally would build the motor first and check your pressure and injector duty cycle afterwards to see if it/they need an upgrade.

People who spin bearings after removing the heads usually do so because they didn't do a clean install. When i did mine i kept the shop vac handy and worked in a clean environment. It makes a big difference, bearings dont like grinding s*** up. Also be sure to change the oil right away and get any crap that did fall into the crank case, out.

another thing that can be a savior many people overlook is upgrading to the GM white oil pump relief spring. It was a nightmare to install but probably the best $3 i spent on the entire build.

[white97z28]

I would be a counter example to both the spun bearing and the fuel pump. Ive had my heads off and the stock fuel pump has carried me into the 12s. Ive made 20 passes since the new setup and have 95k miles now.

Not saying an upgrade isnt a good idea but I personally would build the motor first and check your pressure and injector duty cycle afterwards to see if it/they need an upgrade.

People who spin bearings after removing the heads usually do so because they didn't do a clean install. When i did mine i kept the shop vac handy and worked in a clean environment. It makes a big difference, bearings dont like grinding s*** up. Also be sure to change the oil right away and get any crap that did fall into the crank case, out.

another thing that can be a savior many people overlook is upgrading to the GM white oil pump relief spring. It was a nightmare to install but probably the best $3 i spent on the entire build.

So should i remove the motor just so i know its done right and less of a chance i will get anything in the motor? And also can you put the spring in with the motor in or does it need to be out?

[ezcruisn71]

Where can i find a gm847 cam for my car? I have been looking everywhere and i can't seem to find where they are sold.

If you do go with that much Cam (large duration, high lift). You would also want to think about raising the engine compression to go with that. The more duration and lift you put in a cam the more Cylinder pressure you are going to loose because of that. To get the cylinder pressure back you will have to raise the compression either by going with smaller CC heads or a thinner head gasket or higher compression pistons. Just a thought.

[white97z28]

If you do go with that much Cam (large duration, high lift). You would also want to think about raising the engine compression to go with that. The more duration and lift you put in a cam the more Cylinder pressure you are going to loose because of that. To get the cylinder pressure back you will have to raise the compression either by going with smaller CC heads or a thinner head gasket or higher compression pistons. Just a thought.

That brought up an interesting thought...with the cc xfi 466 am i going to want to have the heads milled when i get them ported? What all am i going to need to have done to the heads at the shop?

[ezcruisn71]

If you are going to have the heads milled then the intake will have to be milled too! The intake will have to be lowered to match the heads.

[white97z28]

If you are going to have heads milled then the intake will have to be milled too! The intake will have to be lowered to match the heads.

Thanks i didn't even consider that.

[meissen]

I had my heads milled and didn't have the intake milled?

[white97z28]

I wondered why i didn't see it anywhere ive been reading up on this stuff lol it must be different for the older 350's

[ezcruisn71]

I had my heads milled and didn't have the intake milled?

It depends on how much you have taken off and what you use for the china wall seals.If you cut .030" or more it will require the intake to be cut also.

[white97z28]

It depends on how much you have taken off and what you use for the china wall seals.

Oh well seeing that i probably wont have much taken off because the cam im going with isn't that big, i wounder...? huh i really need to find a guy to do it first then figure out whats getting done...

[JoeliusZ28]

If you are going to have the heads milled then the intake will have to be milled too! The intake will have to be lowered to match the heads.

nope, i believe you are fine until you mil about 30 thou off. I did .020 on mine, lined up like i hadnt changed a thing.

edit: just saw your second post lol. In any case ive never heard of anyone taking more than 30 off. youre going to start cutting into the valve at that point. .020 and impala gaskets got me to 11.4:1

[Phantom409]

Alright i will let you know if i decide to go with that cam...may i ask why you never used it tho?

Wasn't for me and I got to keep it.
The person I was doing a build for went the other way and picked up a custom grind for bigger displacement.