Hey all! I am working on a 74 'Vette with the 454 and manual 4 speed, and i'm looking for a new engine. Sadly it looks like the people who owned the car previously before our customer failed to use oil with zinc or any zinc additives, so it took out the exhaust cam lobe and lifter on #2 and began to eat at other lifters and lobes as well. To save time they are wanting to just get a new engine rather than rebuild this one- the #2 lifter had probably a good 1/8th inch or more ground off the bottom of it so metal is likely everywhere inside the engine and the whole thing needs to be rebuilt and cleaned throughly. So, I'm trying to find a good replacement engine and wanting to get away from the flat tappet cam, but having a hard time finding options. I like Blue Print engines, but they said over the phone that sometimes fitment in Corvettes can be weird because of exhaust and some other things (originally when we talked to them we were looking at a fully dressed engine instead of a long block but now looking at long blocks instead), and they also said they're processing orders out into February of next year right now. Other options are scarce as it seems every other site either only carries options with the newer blocks that dont have a provision for a mechanical fuel pump, or are basic long blocks with the flat tappet style cam and lifters still in it. So just looking for any good recommendations on roller cam engines basically, if any exist already built other than blue print. Also is there any difference in 454s for Corvettes vs. any other vehicles that had the big blocks? This car doesn't have power brakes either. Thanks

 

The problem is you need a Mark 4 block and they have been out of production for almost 20 years........so you are building and engine if you want one.......
But I would call Mark Jones (VortecPro) in Georgetown Texas.......he has Mark 4 blocks and build "semi crate" assemblies form GM castings...and it would bolt right in your car.....it will also make waaaaayyyyy more power than what you have......I have been to his shop, I have had machine work done by him.....and his older machining threads here have lots of pics......

VortecPro - Racing & Machine - Homepage (vortecpro454.com)

Jebby

 

You can buy a new crate 454 directly from Chevrolet:

https://www.chevrolet.com/performanc...es/lsx/lsx-454

Jegs has two in stock.

https://www.jegs.com/i/Chevrolet-Per...17357/10002/-1

Won't be cheap to make it fit, but just imagine...

 

I would second Vortecpro. I am running one of his 496's.

Pat

 

I am thinking an LS7 from a wrecked Z06...

 

That's how I got my LS6.

 

Umm, not a big block bro. Definitely not a bolt in.

 

Did some looking super quick and summit has a 427 big block. https://www.summitracing.com/parts/nal-19331572. The problem with any crate motor is the supplied intake probably won’t fit the car. Hood clearance is a thing particularly on a big block. Personally I’d look for long/short blocks and try to reuse the existing intake/carb combo. If you go with a short block I’d either pickup some oval port heads or have the OE heads gone through.

You can find quite a bit out there crate motor wise for a big block but 99% of it is targeted at the racing crowd thus is raised deck/raised exhaust port location etc thus are likely to cause fitment issues in the car with exhaust etc.

There are a couple of things bear in mind also. Big block engines have evolved and are separated into generations (Mark IV, Gen 5, Gen 6). If a crate motor uses a Gen 5 block avoid it. No good. If a crate motor uses a Gen 6 block then you might be ok. If the customer is currently using a mechanical fuel pump make sure the engine has the provisions for it. Depending on the casting date and foundry Gen 6 blocks have fuel pump provisions and clutch linkages. Again not all are, so if you look at a Gen 6 crate know this. This is minor but there is also a difference in that the Mark IV uses a two piece rear main where the 5 and 6 are a single piece. Because of that the flywheel/flex plate is different. That’s not a big deal and there are plenty of flywheels/flexplates out there for the single piece rear main to bolt to a TH400/Muncie. There is also a concern about heads and head gaskets between a Mark IV and the newer generation motors. I don’t know enough offhand to know all the details but there is a compatibility that I believe was corrected in the Gen 6 using the correct gasket but double check me on that.

Edit: Wanted to add a few more things. The Gen 5-6 engines by design run roller lifters. This is obviously a huge advantage cost wise. The timing cover is also slightly different. There are two bolts missing in the cover vs the Mark IV. The boss is on the block they just aren’t machined. That’s an easy fix but something to be aware of.

 

The only comment I'll make is that in my opinion true "CRATE MOTORS", come from the manufacture (aka. GM, Ford, Mopar, etc.); the rest are something that somebody else conjured up, which is O.K., but just not what I would define as a true "CRATE MOTOR".

But this does mean that there probably isn't any true graduated "engineer" involved in that product, other than that of the true crate motors, meaning that the other product may suffer in any real "engineering" execution including parts selection, required machine work and assembly efforts; and though there are some that may generally produce an acceptable, to even a fine product, unfortunately in my experience most of the "stuff" is poorly executed, and believe me, the fantastic warranties implied, will evaporate the minute you have any problems!

In this industry particularly, you will receive only what you pay for! So if it's cheap, it's just "cheap" and it's going to cost you!

Scott.

 

Unless I knew the reputation of the engine builder, I'd go with a GM Performance Parts catalog crate engine.

I do have a ZZ4 GM PP engine. My BB is custom made. Ace Engines in Torrance Ca. 630 HP, 492 inches, cam with acceptable street manners.