Chevy 305 heads

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tpangle85

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Anybody have an idea of what the average price to get a valve job on a set of 305 heads runs? I have a burned valve on the number 7 cylinder and the valve seals are definitely leaking. Not knowing the mileage I was thoroughly surprised at how good the cylinders looked and compression was at 150 on all cylinders but 7 so I'm definitely keeping the motor for a while. Just trying to decide if I should spend the money on some flowtec aluminum heads at $450 a piece or just have these heads reworked.
 

Rickf

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I would get a guesstimate from a local machine shop first.
 

Catbox

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We have been looking recently and refurbishing a set hovers around $500.
Give or take $150 depending on the work needed and condition of the parts.

We have pretty much settled on buying a new set when the time comes for the small blocks.
For the big block, we will probably get a set reworked.
 

Ricko1966

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Anybody have an idea of what the average price to get a valve job on a set of 305 heads runs? I have a burned valve on the number 7 cylinder and the valve seals are definitely leaking. Not knowing the mileage I was thoroughly surprised at how good the cylinders looked and compression was at 150 on all cylinders but 7 so I'm definitely keeping the motor for a while. Just trying to decide if I should spend the money on some flowtec aluminum heads at $450 a piece or just have these heads reworked.
My 2 cents unless the price is close to the 450.00 mark get your heads worked and run them. Unless you plan on keeping the 305 forever. Reason being you can spend the money on good heads when you build a 350,383,406 but the 305 heads have to run small valves to prevent interference with the cylinder walls.
 

Bennyt

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If it really runs that good, I'd probably pull just the one head and have the bare mininum done. Probably spend a $100 at the shop plus some gaskets. Do the seals yourself on the other head on the truck for $20 in parts. You can save the money towards a 350 swap.
 

Bennyt

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Really want to do it cheap buy 1 valve and a lapping kit. I even went further than that on a GMC V6 305 and got used valves. Used that truck for 15 years on dump runs.

Are you talking the early 60's V6 305? I had one in a 62/63 I shortbed stepside I bought, it ran great but I think that engine weighed 2-3x a sbc.
 

Ricko1966

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Really want to do it cheap buy 1 valve and a lapping kit. I even went further than that on a GMC V6 305 and got used valves. Used that truck for 15 years on dump runs.
When I post things like this I get flamed and called a hack by another member who shall remain nameless. Every repair ,especially repairs that aren't meant to be forever fixes, don't require a trip the machine shop and all new everything. To lap 1 Valve should you choose, you can put the valve in place,slide a piece of fuel line over the valve stem stick a bolt in the other end of the fuel hose. Now you can spin the fuel hose back and forth between your palms to lap the valve,all you need is a tin of lapping compound. When you think you are done,valve spring back on,smack the valve open and shut a couple of times with a hammer. Now fill the port with diesel,kero,whatever. If it holds liquid it will hold compression.
 
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fast 99

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When I post things like this I get flamed and called a hack by another member who shall remain nameless. Every repair ,especially repairs that aren't meant be forever fixes, don't require a trip the machine shop and all new everything. To lap 1 Valve should you choose, you can put the valve in place,slide a piece of fuel line over the valve stem stick a bolt in the other end of the fuel hose. Now you can spin the fuel hose back and forth between your palms to lap the valve,all you need is a tin of lapping compound. When you think you are done,valve spring back on,smack the valve open and shut a couple of times with a hammer. Now fill the port with diesel,kero,whatever. If it holds liquid it will hold compression.
Jut tossed that out because others may not have the knowledge to cut corners. Yes, spending $500 on head work [actually doubt it can be done that cheap] may not be in others budget. OP may not know something like that can be successfully done. To get it on the road for a year or 2 until money can be saved for a better motor [350] makes more sense.

Would never suggest cutting corners on customers vehicles for warranty or any motor used hard and needs to last. Do it on one of my own vehicles or a good friend sure, all day.

Have watched your posts you sound like an experienced tech. I have actually learned some. Personally, don't care if I get flamed. Usually, it's somebody that reads out of a book, has never done the work or likes to stir the pot. Most of my posts are lessons learned from making mistakes [lots of those] or years & years of customer repairs.
 

Ricko1966

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Yes even sometimes customers don't have money, and just need to get to work until tax refunds, I've cut some serious corners for some people like that,and make them aware this might run a week it might run 10 years. But if they can keep their job,that's the important part. Some of these people have thanked me years later,and told me it ran a long time. I never do anything I don't think has a fair chance.IDK how many engines I've done rings,rod bearings and a valve job,confident they'll get at least 50,000 miles out of it.Some people have unlimited cash and some are barely surviving and I'll try to help them survive.
 
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fast 99

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Back in the late 70's and early 80's we did a bunch or re-rings. Motors at 80k burned oil or had burnt valves.

Tore them down, cut the ridge out [didn't matter what the taper was] cleaned ring groves, pressure washed the block. All white box rebuilder parts, cast rings, berry hone, main, rod bearings, reground cam, timing, and gasket set, HV oil pump and rebuilt heads. Swapped in used parts from core engines as needed. Usually didn't replace cam bearings, pushrods or rockers.

Would last another 40k or so. By then rest of car was worn out. Common vehicle price was around $1000 total parts and labor and we still made money. Took them on as fill in. Always had 2-3 waiting.

Much simpler times.
 

Geoduck

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Travis, I'm in exactly the same situation you are now. 305 engine is bit over 200K and the heads badly need rebuilt.
I got a pair of rebuilt Vortec heads. 520 and 059 Vortec castings flow amazing with small chambers that match 3.8 bore.
Flowtech aluminum heads fit four inch bore with 64cc chambers if I remember correctly. Not a great match for our engine. The ones I looked at had large valves that would hit a 305 cylinder bore. Maybe some have smaller valves? Edelbrock makes a specific small bore 305 aluminum head but around $2K a pair much too expensive for me.
 

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ChuckN

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Travis, I'm in exactly the same situation you are now. 305 engine is bit over 200K and the heads badly need rebuilt.
I got a pair of rebuilt Vortec heads. 520 and 059 Vortec castings flow amazing with small chambers that match 3.8 bore.
Flowtech aluminum heads fit four inch bore with 64cc chambers if I remember correctly. Not a great match for our engine. The ones I looked at had large valves that would hit a 305 cylinder bore. Maybe some have smaller valves? Edelbrock makes a specific small bore 305 aluminum head but around $2K a pair much too expensive for me.
Cool find. Would those have been off of something like a mid-late 80s Iroc-Z or something like that?
 

Copymutt

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Check bone yards for pricing for a head. At the very least have the replacement magnafluxedto be sure no cracks, condition of sale.
 

Geoduck

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Cool find. Would those have been off of something like a mid-late 80s Iroc-Z or something like that?
As I understand it most came from trucks.
Jim makes an important point. Many of those heads have developed cracks. I bought from a trusted automotive cylinder head machine shop to ensure no cracks or other issues.
 

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