I have a couple ??'s that someone out there must know. First off.. I have a cam in my car, and am unsure of the piston/valve clearance that I will have, as the heads are LS6 heads that were milled for compression. I guess the first ? to ask is how would I go about measuring the heads to see what was milled off fo them.. I'll need to know for pushrod lenth also... as I am assuming that the 7.4's that I have in my car will be too long. Also, is there any formula or whatever to check the p/v clearance, if XXX head is milled and cam lift is XXX is there a way to calculate if there will be an issue? the cam is a 224/228 581/588 lift, nothing insane, but if the heads have been milled, I assume that there is a possibility for a problem. Also.. what head gasket is everyine reccommending these days? I think that regular GM headre gaskets are fine, and I think that those and the head gaskets are the only ones that I will need.

I would like to try to do this swap on my own if at all possible... I was planning on going with ARP head studs, not sure on what head gasket yet.. and I"m sure that a shorter pushrod will be needed. Is there any other hidden potential issues with doing this myself? I know that the bolt holes have top be 100% free from water, allt hat kind of stuff, I'm jsut wondering where the potential problem areas are for the job. I'm pretty good with a wrench, and have worked on plenty of stuff over the years.. but never dug into a LS1 motor before. I assume the same care and thensome is needed, but I was wondering if there's any quirkey spots that could give me a problem. One being the headers, do they need to come out, or can they just be unbolted from the head and loosened at the Y and pulled aside.. that kind of thing.


Any info would be appreciated.

 

TTT please.. ther must be someone on here that has an answer to some of my questions......

 

If you aren't changing the cam - http://ls1howto.com/index.php?article=3

If you are changing the cam - http://ls1howto.com/index.php?article=3

Checking for P-V clearance is something I've never had to do, so you will need to either search or let someone else chime in on that. You basically put clay on the pistons and see where the valves hit, or something to that general idea.

 

http://www.ls1howto.com/index.php?article=3

I have no idea about the clearences.
EDIT:777 Beat me too it

 

Nope, the cam is staying in, so that should make the project alot easier. My biggest concern is the p/v clearance, the clay method is something that I am farmiliar with, but what I really need to know is a measurment on a factory 243 casting, and a way I can measure the ones I have to see whow much has been milled for pushrod lenth, and if there is any other possible gemoerty/intake issues with the milled heads.

Thanks for the link though, that does make for good reading, and gives me some more ideas as to how the project is.

 

I'm not so sure you can install the heads with the studs in the block while the engine is in the car. You're probably gonna have to put the heads on the dowels and then screw the studs in place. Kinda a pain in the ***. Course you may already know that. I've seen the the deck thickness measurement flying around here somewhere. Might start another post with that question in the topic.

I've always used a real light checking spring in place of the normal valve spring installed on both #1 springs and the head installed with a used gasket. You can usually find some springs at a hardware store that will work. Leave off the other pushrods in case there is contact. Roll the engine over slowly by hand and continuously push down on the retainer until you feel the piston. Keep rolling it over until you get to the tightest spot and use a feeler gauge like you were checking the lash to measure clearance. If you're really concerned about contact, this is the only way to do it, IMO. The clay method works but if you have no clearance you'll bend a valve, pushrod, something will give. With the light checkspring you can feel it get tight before you turn the engine all the way over.

 

I might have to use the light spring method, just have to pull one of the REV dual springs off the heads that are on there.

I'll see if I can find the measurment somewhere.. maybe search will be my friend today. If not... and someone happens across the thread or the measurment, please lemme know.

Not sure if I should even be concerned with a 224/228 581.588 cam, it's not really that bag and shouldn't be a probelm, but better safe then sorry, if I choose to do this myself... which I just might. The saved labor will go along way towards the TH400 tranny fund

 

I'm still waiting on my heads to be finished. I used the LS1howto.com instructions for the head removal and that was fine. Nothing to difficult to remove those heads. Just unbolt those headers and loosen the Y pipe and move it out of the way. Can't really help you with the clearance problems. Good luck.