100% China/Proform rockers.....spot them easily....china rockers usually have the roller tip pin pressed in and literally broached through the other side sticking out......premium manufacturers do not do this....plus they are the right color blue.....you can buy these at Pep Boys in a skin pack on the wall in their performance section.
Which leads me to ask a lot of questions.
First....what exactly in the pictures are you talking about? Sorry.....I just don't see it.....
Second....the only way to know what size the engine is would be to pull the heads or oil pan. I would do both. You have a lot of money sitting there....if there is no build sheet (which it seems there never is anymore and is one of THE most important things that a novice will throw in the trash or lose) then opening up the engine is an afternoon and some gaskets. If I had bought that the engine would already have the heads and oil pan off. Why you ask? Because any "pro" engine shop that uses a $2500 block and put $125 rocker arms on it shouldn't be in business and they are not anymore....and it makes me wonder what else they skimped on. What heads are on it? Is there any identifying marks cast into them around the rockers and springs? Pulling the heads will give you the bore and stroke. Pulling the pan will give you the piston/rods and crank manufacturer. You will see what style of lifter/cam and be able to easily measure lift. The underside of the head will give you chamber/valve size and with the piston info you can figure out compression ratio......if you pull the cam, the grind number will be on it as well. Poof, you have a build sheet and while you are looking at things you can determine if anything looks out of place......you could do this for less than $200 and your time. Bargain.
Dart block 434's are a $10,000 question now anyway you slice it.......it is worth it to protect your investment.
Lastly.....if this is a 434.....you will be VERY disappointed going to a 383.....totally going backwards.
Investigate what you have and stick with it.....
Any other engine pics, especially the inside will be very helpful and we can identify most anything you have here.

Jebby

 

I was thinking the same thing, but by the comments, it seems the new owner has already written this engine off for some reason. even though he stated it has barely any miles on it. I'd love to have even a 406... the second rocker in the photo is touching and wearing on the spring retainer.. the roller on the valvetip has had bearing failure. I missed it too at first.

I noticed those are not hooker sidepipes either... The welds look a lot like my OBX stainless pipes which I know were less than half the price of the hookers 7-8 years ago when I bought mine so something doesnt add up... Either the car was purchased by someone else along the way that was price conscious or budget driven.. or maybe we know one reason that shop went out of business? The owner could have paid for one thing and got another while the shop pocketed the difference. (Not that theres anything wrong with using lower cost components in some cases but in others such as the rockers it can cause what we have here) I found photos myself that show those are an older model of proform rockers. most vendors have updated thier photos and the links above are for different model rockers such as the LS1 but those are definitely proform rockers... I have some proform stuff myself but generally I like to stick with stuff that has no moving parts when it comes to very budget oriented brand parts... My intake manifold for example which im porting out to match my new heads anyway.

It does have a pricey edelbrock water pump so maybe the budget parts were later addons?

 

Yes they look like some of the knock off import rockers from the 90's. I had a set that did exactly that after a while. They came with a set of really nice heads I bought and admittedly they had some stout springs on it...but they had pins slipping out and rollers wearing oblong.

JIM

 

I don’t know why my post earlier didn’t go through.

Yes, they are an older Proform rockers. I think they came on the aluminum heads, which look nice, no name etc on them though I haven’t looked super hard(back of heads etc).

This car was built nice, some stuff done nice, some not. Example nice new power steering system, no power brakes, but disc brakes. It is a handful to drive the clutch is ridiculously heavy, 2x my 67 big block car. In 2019 my right leg was crushed and it is very painful to drive this car, but it is my favorite car to cruise in.

I know a lot of you are saying 10k question, you can get a dart block for under 2k, big deal. This car was purchased at the bottom last year, from a 20+ car owner unloading everything quickly and cheap.. Long story on the car. I purchased it to be a cruiser. I do not want as much power as what it has right now, I want to put a Holley Sniper system on it and be reliable, maybe even going to a 4L60E in it. If I want performance either I will get a ZR1, Z06 or Callaway out. If I was going to do performance in this car I would be doing SO much more to it than where I want to go.

I have no need for a build sheet on the car’s motor because this winter more than likely it will get a SBC crate engine of some sort. Also if I really wanted power I would do a LS/LT with a bunch of boost in it. I have a LSx 427 setup for twins and 1200-1500hp sitting in the shop, already has a terminator x on it and I have a 6L80E for it as well.

 

Well if you want to off load this engine I am sure someone will buy the short block for sure.

 

LOL there is already a line for it