Found signs of coolant in my valve cover. 5.3 with 706 casting. I've read about them cracking but also read that some run them. It isn't horrible but it's obvious that there's been coolant in the valve cover. I really don't need aftermarket heads for my application . So can these heads be repaired? I found 862 heads at the salvage yard for 125 but can't imagine they are worthy of installing without a valve job or maybe? I would like to know what others have done to replace/repair these heads. I only seem to get e Bay sellers when I search for replacements. A referal to a reputable machine shop for the ls engines would be nice also my local shop does not do them. If I have to buy refurbished performance heads like from Texas speed I will but I really want to save for other areas of my project. That being said what's a good valve job on these engines run? Is it worth fixing the older castings?Thanks for any advice Charlie .

 

IMHO ,, heads are a item where "no dollar is wasted" nothing else makes as much difference except maybe the pistons for the $$ spent. I can get a shop to do a basic 5 angle valve job on a set of heads for about 300 on average in Oregon. (No trick head porting etc..)

A machine shop can crack check them for you.. Locally its 150 bucks to check the head and do a cleanup cut on the gasket surface..

 

if the 706's are indeed cracked they're not worth repairing.

make sure you ask how they are pressure testing them. i have seen heads get "pressure tested" by bolting the head down to a plate and blowing air into the sparkplug hole. this only uncovers cracks from the chamber to the water jacket, which is not what happens on the 706 castechs.

862's are fine, no known cracking issues with them. small valves like the other "truck heads" but they have a small chamber too.

i guess it all depends what youre trying to do

 

Thanks for the replies. I have a 5.3 lm7 was supposedly "low miles for a swap.
ls6 manifold/injectors/tb
new 212/218 .550 114lsa texas speed cam and ls6 springs new from them too.
I was hoping the long block was good since I bought it from a car guy and it was so clean. The passenger side is very clean but I have not torn it down at all just looked under the cover. It's not a high performance build but I can't run it **** house but man I really didn't want to build a short block and by expensive heads. Too many stories of " I just dropped it in". I have alot of money in the car and just ordered a new tranny and new tc and new harness and new everything else! But iam not stupid so I'll pull the heads,and pan and pull a main and check a beating and see what I find but that always end in a new short block doesn't it. Would I be better off with aftermarket heads? I saw some from a vendor for 1300-1500. Which is a lot but no guess work. I had this idea of cheap because it was a truck motor not custom built performance build lol. Not really a race car but maybe I should tub and cage it and do what you guys,are doing with turbos?

 

Seems like you can get heads from Rock Auto a little cheaper than from a vendor here.

 

Ok so stock heads from rock auto are worth running? Or salvage yard and rebuild? The others are the cbc big valves ect that's the 1300-1500. If you know these would you mind giving me a year and model so it's easier to search. Thanks

 

salvage yard, lap the valves, new springs and valve seals. run it.

 

Heres what it looks like. Over reacting? Deffenitly coolant .what do you think? Thanks


Other head looks much better

 

Are they castech heads? If you pull the rocker assembly off of the head with the coolant in it, there may be a casting mark shaped like a AA battery. I believe they leak around the area where the head bolt boss is cast. Worth looking. If it were me and they are castechs, pitch em.

 

Nevermind! I freaking hate liars and thirds! How could you do all this to deceive someone into a wreck? A-holes!!!!!! Looks like my plans have changed **** goddamn can't catch a break this life, maybe next.

 

Similar to one of my experiences. Bought an LM7 from a guy on here and when I got it and looked it over it was junk. Guy said it had 100k on it. the block on the outside was rusted to ****, and when I pulled the heads it looked similar to what you've got going on there. 4 of the cylinders were covered in rust and had a pool of water in them. Thank god I didn't run it. Guy never returned any of my messages. Learned my lesson though. Next time pull the heads to inspect before you do anything.

 

Yeah my fault I didn't inspect it enough. I just couldn't do that but I guess others can .

 

yikes. you might be able to save the block. if that much water was in the oil the bearings are probably beat

 

how far over can these bores go? If this was a gen1 it would clean up at.040 if it's not cracked somewhere from heat. That's the thing the lower end looks ok, it got real hot you can tell and smells like a dead superstock motor and I'm sure it need bearings but it doesn't look as bad as the cylinders. I got a quote of 2200 for a stock partsrebuilt long block locally. Is it worth it? Nice to know at least it was actually done. Any other advice on reputable machine shops or used engine shops. Ism about ready to just buy something I can trust.

 

I would look at http://thompsonmotorsports.net/ there prices on ebay are better or https://www.high-performance-engines...ory-s/2170.htm

 

if you got the dough, sure. my next step would be to put that thing through the living room window of whoever sold it to me and then buy another pullout. just make sure it spins over easy. you can also peek in the bore through the plug hole with a pen light.

people take them the ~.100 with sonic checking so .040 is probably fine.

it all depends what you're trying to do.

 

can't decide and have a history of over thinking and spending on ****. I have a mechanic friend who felt sorry for me and offered me 5.7 take out but we all know how hard it is to get a good engine by luck. I've built several old small block and raced a bit and so I know how fussy machining engines and assembling engines can be. I wanted to do this because I love how the kids are digging through junk and mad scientisting 500 horse engines. Bad news is I'm older and have a family and to many responsibilities to be digging through junk just because of time. I'll drop off this block at the machine shop and see what they say and I'll go look at the 5.7 my buddies offering too, never know might be a better start. If I have to go ground up I'll have to re think it I guess. Sucks I all ready purchased most everything around this motor but most interchange right? I live in Montana and it's small and I've never seen a truck that didn't have 200k + lol! Mines got 240 . But I'll call some other near by recyclers and see what a running pull out would be. 2200 sucks but it's piece of mine. The fancy ones are maybe too much, I know they are awsome but I don't want that much money in the drive train or my wife might be un pleasant to be around. I still gotta pay for upholstery as well and those guys are ******* special as it turns out lol. Maybe I'll start a questionnaire about potential combinations. Thanks guys I have alot of fun on forums and it's all ways more fun when guys reply and are nice. Iam open to suggestions as iam sure all of you are much more knowledgeable than me. I pulled a running flathead out a this thing when I first got it and have it to the high school auto shop lol! Have a great day it's Friday woot woot!

 

BBJ auto on E-bay, good folks and reasonable prices...

 

yeah have a look at the 5.7 and go from there. if that 5.3 were properly maintained, 220k would have been no problem. the 6.0 i have turbocharged has 260k on it and is just getting started

 

Check out pro tree racing in fort Worth. They rebuild engine for I think $800 with exchange.