How important are orginal heads on a numbers matching engine?

AyWoSch Motors

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I pulled my numbers matching engine out of my truck recently becuse it decided to blow up on me. Decided to throw a brand new 350 in it for now, so I can get back to daily driving it.
Anyway... I decided I'm going to keep the original engine, so someday if I ever feel ambitious and want to rebuild it, or if I ever sell the truck and can advertise that it has the original engine. Just planning for "someday".
I just bought a blown up vortec for cheap to use as my core, but I dont want to give away the Vortec heads, because they're gold nowadays, but the company I'm buying the engine from requires the core to have heads. So I was thinking of throwing my old worn out 305 heads on it before I give it away, but I was wondering if it would be important to keep the original heads to go with the engine.
Does that effect the value of a numbers matching engine?
 

Ellie Niner

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If you're going the numbers matching route, the more original stuff you've got, the better. If you're planning a high level restoration someday, I'd hang on to everything.
 

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I wouldn't sweat it much, especially for a truck that came with a 305. If it was a big block or something then that would be more desirable to hold on to for the future. Not all but most buyers of these trucks would want to see a high power engine vs a wheezy stocker.
 

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I wouldn't sweat it much, especially for a truck that came with a 305. If it was a big block or something then that would be more desirable to hold on to for the future. Not all but most buyers of these trucks would want to see a high power engine vs a wheezy stocker.
i could be wrong but dont 305 heads have a place for people with 283s or does that ultimately end up in the same boat as a 305 aftermarket head being probably better in most ways?

edit: basically bringing up so maybe someones 305 junk can go to someone else for actual value :)
 

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I think everyone has a different opinion and in the end the value of those heads is up to you and any prospective buyer. Also as people continue to throw away 305's because they some think they are junk, there will be fewer and fewer.

Think about it. Remember when no one wanted in inline 6, everyone had to have a V8 now a inline 6 with a 3 on the tree is something special because so many are gone.

Also for me at least if I were looking at a numbers matching truck, complete and running matching engine would be best, if it's out of the truck and the heads are missing I don't see much value in it. If it's out of the truck worn out and complete at least it's all there.
 

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Think about it. Remember when no one wanted in inline 6, everyone had to have a V8 now a inline 6 with a 3 on the tree is something special because so many are gone.
The same with th350's! I had one hell of a time finding one when mine died... let alone 2 when i blew it again! 1 more time and i was gunna sm465 it!
 

AyWoSch Motors

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Well, I dont have much attachment to them, other then they were on my truck when it left St. Louis in 1986.
I probaly wont ever sell this truck because it's my baby, but I dont really want to just throw away my 305 becuse it's not completely junk, and "someday" I may rebuild it. So I guess the numbers matching thing isn't a big deal.
I like the idea of having it an all original truck, but for now I need it to be running and reliable and at a point where I wont worry about it. Insert new 350.
I'm not one of those people that says all 305s are junk, and want to get rid of it. It was in this truck for 35 years, and has served me faithfully for the past 3 years. It just happed to die, oh well. I have no problem with them personally, although I have heard some rumors, Haha.
And ive checked values, and 305s are notoriously less valuable than other small blocks, but your right, and someday they'll be rare and sought after. Like 283s are now. Damn, they're hard to find nowadays.

The heads aren't exactly perfect, they have their issues. Mainly that a couple of the valves are mushroomed over, and just a overall look of tired. They'd have to be rebuilt anyway.
So...
 

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@AyWoSch Motors My truck is a 305 it was swapped before I got it so it's not the original, though the original was a 305. It's fine, it does everything I ask it to, but slower with the trailer than I'm sure a 350 or BB would be. Like you I'll keep the 305 until it's done, then? I haven't really decided as you know it's just as easy to throw a 350 in, than put a 305 back in. I don't have the numbers matching concern so there is that. A BB would sure be nice when I pull the big trailer, but there is more work to the swap and I'd pay the gas if I continued to daily it. And then there is the matter of the 700R4 that's in there. I should get a plan in place for when the time comes, and you might be able to help me with that.

How do you like that 350 vs the 305? And is the new 350 just a stock engine?
What tranny you running?
Do you know your rear end ratio?
Thanks.
 

Ellie Niner

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I've been driving my truck for over 20 years with its original 305, and I honestly can't come up with any good reasons to not rebuild it when the time comes. I know I'm supposed think it's a pile of hot garbage, but, to be honest, it's been doing the job better than it probably should considering that it's lugging a 4800lb brick with 3.08 gears and an overdrive that puts it in Bonneville Salt Flats territory. If I drive at O.J Simpson speeds, I can also knock down an honest 15-16mpg on the highway and secondary roads.

Not a popular opinion, I know, but if I can get 80% of the power of a comparably equipped 350, and net a couple extra miles per gallon... my terminally empty wallet appreciates it. And actually, the LE9 variant feels like it has more cajones than the lower compression 350 in my 1975.
 

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It's not a Corvette, Chevelle, Charger, Mustang, etc. whose buyers will pay considerably more for a car with 100% original parts. Chevy stamped the deck of the block and transmission with the last 6 digits of the VIN. No other parts have any indicators on them that say they belong to any particular car. Casting dates help but they're not set in stone. If the intake manifold or water pump have ever been swapped, true originality is gone. Your old truck will be worth zero more with the original heads than it would be with replacements. There were way too many of 'em sold and still way too many of 'em on the road than any of the muscle cars that are valued on originality.​


Sorry about the font size, I tried to change it and it kept returning itself to big and bold.
 

AyWoSch Motors

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It's not a Corvette, Chevelle, Charger, Mustang, etc. whose buyers will pay considerably more for a car with 100% original parts. Chevy stamped the deck of the block and transmission with the last 6 digits of the VIN. No other parts have any indicators on them that say they belong to any particular car. Casting dates help but they're not set in stone. If the intake manifold or water pump have ever been swapped, true originality is gone. Your old truck will be worth zero more with the original heads than it would be with replacements. There were way too many of 'em sold and still way too many of 'em on the road than any of the muscle cars that are valued on originality.​


Sorry about the font size, I tried to change it and it kept returning itself to big and bold.
Thank you. That's sort of what I was looking for.
Yeah, the intake, carb, valve covers, timing cover, cam, water pump, all that has been changed, so is not 100% anyway. Not like it's ever gonna be Concours quality. It's a truck, its supposed to be used accordingly, I'd never make a sissy little museum peice out of it. Its meant to be used.
 

AyWoSch Motors

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I've been driving my truck for over 20 years with its original 305, and I honestly can't come up with any good reasons to not rebuild it when the time comes. I know I'm supposed think it's a pile of hot garbage, but, to be honest, it's been doing the job better than it probably should considering that it's lugging a 4800lb brick with 3.08 gears and an overdrive that puts it in Bonneville Salt Flats territory.
Full agreement there, I always line mine. Had balls, and it did everything I needed it too.
It hauled rock, it could haul a trailer, it cut the mud like no bodies business, did 100mph on the highway once, beat lots of kids between stop lights, haha.
@AyWoSch Motors My truck is a 305 it was swapped before I got it so it's not the original, though the original was a 305. It's fine, it does everything I ask it to, but slower with the trailer than I'm sure a 350 or BB would be. Like you I'll keep the 305 until it's done, then? I haven't really decided as you know it's just as easy to throw a 350 in, than put a 305 back in. I don't have the numbers matching concern so there is that. A BB would sure be nice when I pull the big trailer, but there is more work to the swap and I'd pay the gas if I continued to daily it. And then there is the matter of the 700R4 that's in there. I should get a plan in place for when the time comes, and you might be able to help me with that.

How do you like that 350 vs the 305? And is the new 350 just a stock engine?
What tranny you running?
Do you know your rear end ratio?
Thanks.
Haven't swapped them yet, but I let ya know the difference when I do.
The 350 I'm putting in is reconditioned, but new. Stock specs, nothing fancy. Will be putting my old edelbrock performer intake and edelbrock 650 back on, so it'll have guts.
Trans wise, I run the stock SM465 with the stock NP205.
Rear gears, i think it's a 3:90 if i remember, maybe 3:73. I'll have to check the glove box. It has a locker too.
 

Bextreme04

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Another thing to consider is that the second you rebuild that block and have it decked, the numbers are going to get cleaned off it anyways. Cylinder heads are not stamped at all, so there is no such thing as numbers matching heads. There are several casting numbers that COULD have come on a 305 in 86, and it probably wouldn't be hard at all to find a set if you ended up wanting or needing them.

The problem with any original cylinder heads right now is that the 70's and 80's truck cylinder heads were some of the worst that chevrolet ever made. Not only that, but any that still exist in stock trim are going to need a cleaning, decking, valve guide replacement, and probably new valves with a decent valve job to be worth putting on a new engine. Once you have bothered to do that, you could have just bought a complete set of NEW, better designed, iron cylinder heads from summit.

Even stock Vortec heads aren't really worth much anymore since they need $300-400 worth of work to refresh(if they aren't cracked... which they usually are) and you can buy a brand new set of vortec or non-vortec 350 heads from summit for ~$700 shipped.
 

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