I am in the middle of pulling my 305 TPI from my 91 Z28 and have decided to replace with a new 350 motor. I will be re-using as much as possible from the original 305 (intake, exhaust, distributor, ac, altenator, power steering, etc.) but I want to know where is a good place to buy a new 350 engine without breaking the back. Someone suggested to me a place called Jasper Engines and the cost to me would be $2500. Thats for an engine block, pistons, cam, crank, heads, timing cover, and oil pan. I think it's reasonable, but I'm looking for any other options or suggestions.

Thanks!

 

I would stay away from Jasper.I have not heard good things about their engines. If I was going to buy a crate I would go to Summit, Jegs, or the like and get a chevy performance engine.

 

I'm not finding much luck on Summit or Jegs. On Summit, for example, I can only find this 350 for a 91 Z28.
https://www.summitracing.com/parts/v...t/model/camaro

It's $1800, but I'd have to install oil pump, pan, and timing over for it to be an apples to apples comparison with the Jasper Engine. BUT this one is a remanufactured engine. So I just wanna understand if its OK... and if there are any other options out there. Also, what's so bad about Jasper?

 

An engine from Jasper is also going to be re-manufactured. the only place to get a NEW 350 is going to be from chevrolet.

 

So the linked engine from Summit is an exact replacement engine for a '91 Camaro. If your car originally came with that engine and you were simply replacing it then that would be what you would need. Pull the old motor out, switch all the stuff over, drop it back in, set the timing and you're done. However you didn't have that engine from the factory, so you're going to have to re-tune the ECU in your car unless you replace your engine with a 305 like you have now.

If you're looking to go to a 350 then you're obviously trying to get more power, so basically you can install whatever 350 you want as long as your current intake and accessories will fit onto the new engine. If you want piece of mind don't buy a re manufactured engine buy a new one, but if you don't mind a reman then go for it. Simply put, any gen 1 small block will drop right into your car and be OK, but unless you put in the exact same engine you're going to have to tune the ecu.

As for my Jasper comment, I talked with a friend that bought one and the motor didn't last more then a 1000 miles before it died.

I am personally installing a used 75,000 mile vortec 350 out of a 1997 tahoe in my '87 IROC and all of the factory accessories have bolted right on, my T5 trans bolted right up to it, it fits in the car perfectly, and it looks factory. The downside was that I had to buy an Edelbrock vortec tpi intake base that cost $400 to make the tpi setup fit. I am now into this engine for $1000 which includes the cost of the motor ($400), intake ($400), water pump ($50), starter ($100), and gaskets ($50). When all is said and done it should be in the 275-300hp range for power, where the 350 in a '91 camaro put out 245hp.

 

Thanks for responding! This makes a lot of sense. The point you made about ensuring everything will fit on the new engine is what I'm most worried about. I was under the impression that for everything to fit without having to modify brackets is to stick with a small block that is considered a "late model" which as I understand is a 1987 - 1995 motor originally setup with a TPI. But when you just start looking for a 350 motor online... there's like a million of them. And I don't know how best to sort this down to the options for the easiest conversion possible in my case (which sounds similar to what you are doing)

Honestly, I'm currently in the camp where I'm willing to shell out $2k - $3k for a new crate motor like maybe something like this:
Jeg's 350/290 Motor

But again, I am not entirely sure if this will work with the existing TPI intake, accessory brackets, and misc sensors that go into the block/heads. When I eye-ball the picture, it looks like everything is in the right spot... but I am not sure if I'm missing something. And I would hate to buy such a big ticket item just to find out that my brackets don't fit!

And yes, I totally get your point... ECU tuning is required in a conversion like this. I will be investing in a programmer setup as recommended on the tuning section of this forum. I am also hoping to ask around my area and see if anyone is proficient in this process and would be willing to pay them to help tune my engine.

 

When i purchased my most recent trans am the prev owner put a jasper 350 bored 30 over. no issues with engine and trans. other issues. but drive train is running great

 

Ha ha yes there are a TON of different small blocks out there, but here is the quick and easy on chevy motors that will concern you. Your factory accessory drive setup, TPI intake, motor mounts, and transmission should fit almost any 350 up to 1996 when the Vortec heads were introduced. If you choose to go with a factory vortec engine then the only change will be the lower intake manifold, the rest of the stuff will bolt on. Vortec heads flow a lot better then the earlier ones, but the intake bolt pattern is different. There are only eight bolts on going straight up and down on vortec heads (two in the front and two in the back with none in the middle), compared to the twelve on the previous heads (two in the front, middle, and back) that were at an angle. the reason is that the coolant passages in the heads are only in the front and rear on the vortec heads. Top pic is the non Vortec and bottom is the vortec.


Regular sbc head

Vortec head

The other benefit of going with the top motor is that your valve cover choices are way better once you get away from the center bolt verity.

 

The problem with using tpi and keeping all the original equipment in tact is there is no good direct replacement made new. You have to go rebuilt for that to happen.
You can get a vortec crate new, but then the intake base needs to be changed. And if you need the egr in place, then you have to route that from an exhaust header or manifold. Vortecs have no exhaust crossover.
The crate you have in post #5 is terrible. Poor heads, poor flat tappet cam (non efi friendly too as I recall). Bolt angles don't line up to your intake either.
Intake bolt angles are something you can overcome by grinding out the holes to make them oblong. I don't personally recommend it but it has been done. Some aftermarket intakes were made that way to specifically work on both bolt angles. Regardless, it's an issue unless you go and find aftermarket iron heads with the matching bolt angles or the factory #193 or #083 heads. 083 are what factory L98s came with and much preferred over the truck 193 heads. People will occasionally defend 193s but I would not recommend them.
The tpi in stock trim (and even modified with aftermarket runners and such) is a bottleneck quickly so performance gains are diminished on a stout engine if that were a route you took later.
If you get a Jasper (we use them at my work in an industrial setting and they haven't let us down but I'm not going to push them one way or the other) you'll need to pay out a core charge since your 305 isn't a 350, and you might not be able to confirm if the cam or heads are L98 spec or just the crap they put in a truck. And Whats the point of moving up 45 cubic inches if you're just going to have similar performance?
You're in an odd spot that me and others here have been. I built my own and fought all the decisions along the way. There is a chance you find a good, used L98 on the classifieds and it'll drop in. All you need is injectors and a tune.

 

So according to Jasper's website they sell a L98 which they label as the "police package". I'm assuming that if I went that route the intake could drop in... but the tradeoff is it would be a ~210 HP engine versus trying to find an adequate crate performance motor around he 300 HP point. And ya... I wouldn't get the core charge back.... so the Jasper engine is $3k.

I totally get everyone's point about re-using the factory TPI... so I guess I should clarify my plans... I really am just saying that I want to keep fuel injection... not necessarily the stock TPI intake setup. I am ok buying an aftermarket fuel injection setup as long as I can keep all the electrical connections the same. So maybe something like a Weiand Stealth RAM that says they can handle the two different angles of center bolts (requires an additional kit for 1987 and later cast iron heads).

So if I wanted to buy an aftermarket EFI Intake and a 350 crate motor running around 300 HP... what options are there? It seems like so many crate engines are for Carburetor intakes... and I'm just trying to make this engine swap the least painful, simplest install, small nudge of performance increase, AND without spending more than $4k for everything. (I'm targeting $3k for engine and $1k for intake)

 

One other thought I had was trying to search for the same year Corvette Engine. So a 1991 Corvette C4. When I search for that on Jegs I found this, which basically is saying you can use the stock TPI intake and it will be a 289 HP engine. Thoughts?

ATK Engine

 

I had an ATK reman LT1 in my 1996 Impala SS develop Combustion products in the cooling system after about a year. When I telephoned ATK, I realized their warranty was nothing!

 

https://www.google.com/search?q=thir...iw=360&bih=612
I have no firsthand experience but search and read. You decide if you want to deal with atk.

 

I have done a few "Ring and valve jobs" that turned out fine and ran for years. Sometimes the less you F-With, the better. When I managed a shop in Santa Rosa CA, we used the same machine shop, for 10 years. Lots of valve jobs and some engine work. Only one problem, that I can recall. But they were EXPENSIVE! The owners grew old and died and that was the end of them. Craft Engine Machine. RIP

 

Hmmm, ok ya searching for ATK is kinda scary stuff. How about Chevy High Performance engines? From some limited searching they seem to be good, but I can't seem to find an engine that won't break the bank AND still work with a fuel injection setup. Thoughts? I posted that one engine in post #5 that I thought would work, but someone above said that engine was no good.

Still looking for suggestions for a crate motor that would work.

Thanks!

 

I know your budget sounds reasonable, but you'll quickly find you'll break that no matter what you do unless you go cheap. Old adage tha'ts popular here, "Cheap. Fast. Reliable. Pick 2" If it's cheap and fast, it's not reliable. Reliable and fast, ain't cheap. Reliable and cheap, it's not going to be fast.
As said before, there really isn't a good NEW replacement. Even straight from Chevrolet. A vortec is the best option. This is feasible Qualifies for your requests but it's already killing your budget. That's just how it's going to be.
If you go rebuilt, a crate is a big gamble. National chains are unconcerned about your satisfaction, and fly by night internet rebuilders care even less. You could get a good one, but being cheap and you can get ATK'd.
A reputable machine shop near you can yield better results but will most likely break your budget just as fast as the new engine from Summit linked earlier in the post.
Precisely why I built my own. I selected the parts I wanted. Had a good machine shop and good parts. And I needed a lot of things that weren't expected in my initial plans. So budget blown.

 

Crate motors are all a crapshoot.

The best source is a Chevrolet Performance crate engine.

Otherwise just get a used Vortec and freshen it up with a basic rebuild and a cam.

GD

 

Totally get it... If a crate is a tad higher than my budget, I can deal with it. I just can't do an $8k engine. But in regards to the "feasible" suggestion... I have seen that engine in my searching. However, what turned me off was the following Q&A on that same link:



So according to Summit themselves, this engine is not to be used with factory fuel injection. Are they just saying that because it requires a re-tune / different injectors / new intake? Just curious what makes an engine not allowable to use fuel injection. I mean... I understand that this won't replace a LT1... but shouldn't it work for TPI?

Thanks

 

More than likely it's due to the camshaft lobe separation angle. They don't show the full specs on Summit but it's probably a tighter lsa which is less friendly to fuel injection. Even their Ramjet 350 they sell (much higher cost) has a smaller cam and likely a wider lsa, though the cam with this isn't large by any means. You could change the camshaft to something more your liking but thats quickly defeats the point of a crate.