I know these things have been asked a bijillion times, and I HAVE READ THE STICKY... so just bear with my please.

I am thinking about buying a GM crate 350 from Scoggin Dickey. $1,750 w/free shipping !!!!

It's there 290hp/350

It's very tame in it's aspects

This 290hp 350 crate engine gives you the most bang for your buck! All new components, not a rebuilt 350 from the five and dime store. 2-year, 50,000 mile warranty* on parts and labor --- backed by GM!
On top of the great price, the 4-bolt cast iron block is jam packed with great components like brand new 5.700" PM steel rods, cast aluminum pistons, and a GM high performance hydraulic flat tappet camshaft. The perfect fit for street rods, old pick-ups, or any project vehicle you have that needs a traditional V8 small block Chevrolet from the General!

Not intended for marine use. Use in 1979 and earlier pre-emissions applications.
*Limited GM Warranty, see our warranty section for details concerning the general information and requirements.

290HP / 350 Long Block GM Crate Engine Specifications:
Horsepower:290 @ 5100 RPMTorque:326 @ 3750 RPMCompression Ratio:8.5:1Block:Cast Iron 4-Bolt MainCrankshaft:Nodular IronHeads, Chamber Size:Cast Iron, 76ccValves (I/E):1.94"/1.50"Camshaft, Lift (I/E):.450"/.460"Camshaft Duration @ 0.050" I/E:222°/222°Intake Manifold:Not Included

I realize I need to find out if the heads are 87+ design to accomadate a TBI intake, or I will just get a standard carb'd intake and adapter.....

I'm going to get a new edelbrock intake (if I can) and Holley TBI unit........
So going by the sticky, all I will need are the 350 ESC module and prom, plus a knock from a 350 as well??

Can I just re-burn my 305 prom to work with the 350?
Do I really need the ESC ifI use a MSD 6A box?

 

So is no-one willing to chime in because this question gets asked a lot, or because they have no clue??

 

Yes you could make that engine run with Tbi no problem! BUT you will have to get a custom tune or a DIYtune to get it to run right. Lots of info in the stickies and other engine swap section to check out.

 

I have ready ALL the stickey's but none of them addressed a pre-87 build-up really. All were just based on swapping the LO5 motor from what I took??

I will have CFM-TECH do the tune, so it should be cool??

Guess my main point is DO I NEED A ESC if I'm gonna use a MSD box and maybe a MSD dist??

 

Yes im quite sure that you will need to swap out the 305 esc for one from a 350. Trucks you dont but im sure you will have to with the cars. Using the msd disty and 6al box wont be a problem as long as you use the correct connections and the proper disty for your application. I would really suggest getting into tuning it yourself! , But at least getting a mail order chip will get you started.

 

The reason that you WILL need aa custom tune is the lca on the cam in that engine is 110 degrees. The ecm wil be unhappy from the start with anything less than 112. most modern fuel injection cams are ground with 112-117 degrees. With custom tuning(vehicle present on dyno,not mail order) any cam can be tuned. Take that with a grain of salt, there are some cams that are too radical for speed density or even that mass air can tame and those will require an Alpha-N style ecm. You will save money by doing a diy tune and be much happier. Of course you could buy that engine and swap for a tbi freindly cam.

 

The cam in that engine is not on a 110* LSA, its on a 114.5* LSA. The problem with the 290 HP 350 is that it is a DOG. Its has an 8:1 compression ratio, crappy heads, and a relatively large cam (224/224@ .050). Its nothing more than a cammed 260 HP 350 crate. Either go with the 330 HO or go to a stock L05. You will be much happier than the 290 horse SLUG. The other engine I would consider is the stock L31 replacement Vortec 350.

 

I have that engine..if you are looking for something which is a good reliable decent driving driver..it is great...but if you are lookgin for something which is a drag race "champ"....look elsewhere.

I still have some bugs to work out since I ran out of time last year, but it ran "half decent" with a stock ANLU bin.

...more to report this year when I take it out of storage and find the time to work on it.

Again its no "race winner"...but I would say once I get the kinks out its probably about the same as a stock L98.

DK

 

Agreed with Fast355. Cam is not TBI friendly and the compression is low. Also, your later TBI intake won't bolt up to the pre-86 bolt pattern without modification.

If you can deal with the intake bolt pattern issues, I'd recommend the base 250-260 HP version of the engine only becuase the cam is smaller and will be easier to tune with EFI and work in a powerband that is more in line with what a near-stock TBI setup is capable of working with.

Even with the milder version of the engine (assumign proper tune) it's going to feel like you strapped a second engine under the hood. I've replaced worn out carbureted 305s with that motor in 3rd gen F-bodies and it was a significant kick in the rear over the stock engine.

 

I am not looking for anything near a "drag race" motor !! I have 2 434's and a 355 in the garage all well over 500hp.....

I am looking for something more than the 170hp 305 that the car came with, but still can be very EFI friendly and easily swapped for under $2K, which is where the 290/350 comes in.... the 260/350 is the SAME price so why not go the extra 30hp??

I can deal with the intake issue, i have several pre-87 intakes and can just get a adapter plate for the TBI itself.

Problem i will run into around here is finding someone to tune the ECM. NO BODY in my area does TBI, all they do is Mustang and LS-Edit crap.

I am just looking to do this swap cause the original motor is pretty tired and I love the car, thus not wanting to get rid of it as I looked a long time to match the same car I had 10 years ago in H.S.

Basically since the 260/350 will require tuning, why would I not jus go the extra and get the 290/350??

The 330/350 is a grand extra for not much else than a cam and some vortec heads (I got 3 sets already) so no big whoopty-doo there. Just wanted to know if it was going to be a major PITA or not, thats all.

 

Because the cam is too big to work with a stock stall converter and tall rear gearing. The 250HP version will get from A to B faster. It's got more torque (to the tune of almost 30 ft lbs) and in an RPM range that will work with the rest of your components much better.

 

Sorry, but the 250hp version has LESS torque, by the tune of 32 more, at 304ft lbs compared to the 290hp version at 326ft lbs.
http://www.sdparts.com/product/10067...MVehicles.aspx

Anyways, maybe just the crate replacement for a 87-95 GM Truck???
http://www.sdparts.com/product/12568...GRUL0557K.aspx

 

The more important details are where in the rpm range do the torque peaks occur, and how much torque does each engine produce at part throttle? The reason why Fast355 said the 290 hp engine was a dog, and has to use a warm camshaft to make up for it, is because the engine is built with slow-burning open chamber style heads. That also means the part throttle torque response will be lousy. That engine only makes good-looking numbers during WOT and that's entirely due to the cam.

You said yourself that you already have big hp engines in the garage... so you don't need another that only looks good, by the numbers, at WOT. The truck LO5 engine is ok, but it's still a flat tappet lifter engine. I'd go with the passenger car version, even though it only has the peanut cam (which cam be replaced).

 

Agreed, I thought he was talking about "overall" TQ specs....

SO the LO5 motor is NO GOOD then??

 

I wouldn't say the truck LO5 engine is no good..... but if you swap the cam with a different (warmer) flat tappet cam, and the cam lobes accidentally wear then you'll have a problem. There's much less chance of that happening with a roller cam, nevermind the +5 hp the roller cam engine gets above a similarly cammed engine using flat tappets ( GM gained +5 hp when they switched from flat tappet lifters to roller lifters in the 1985/1986 Vette L98.

OTOH if you buy the truck LO5, it will have provisons for using roller lifters in the lifter gallery area. So if you added the roller lifters, and retention spider plate, then it's all good.... you will have duplicated the passenger car LO5 configuration.

The single added caveat is that both the car and truck versions of the LO3 and LO5 all use swirl port heads. They aren't junk like all the old TGO threads would mislead you to believe; they are fast burn heads but they are also not fast-burn high-flow heads (like Vortecs). So the usual tradeoffs apply if you don't port them, or replace them with L31 type heads.

And there are many more-recent threads that discuss the tradeoffs involved. HTH.

 

Your torque specs on the 250HP version of the engine are incorrect. It's 350 ft/lbs or 360 ft/lbs, depending on where you look. 304 is a misprint that's gotten around here and there including on Scoggin Dickey's website. The correct number from GM is 350 ft/lbs. Also, torque doesn't peak in the 290HP engine until 3750 RPMs. In the 250HP version I believe it's 3250. That's a big seat-of-your-pants difference.

The difference between the 2 engines is purely in the camshaft. The cam in the 290HP version has almost 30* more .050 duration than the cam in the 250HP version. That's an awful lot of duration in a mild 8.5:1 compression motor and the torque curve suffers becuase of it, although peak horsepower is higher.

If you're trying so hard to convince yourself the buy the 290 HP version then do it. You probably won't like it near as much for what you're trying to do but it's your money. Have fun.

 

Thanks for the info...........

So maybe if I will most likely need to change out the cam anyways, should I possiably just get the short block, use a set of vortec heads I already got, and a TBI Vortec intake?? Might actually be money in the bank??

What cam is reccommended for a TBI motor? I know the LT1 cam is good, but would like a bit of a "lope" to the idle (obviously going to need some MAJOR tunning) but does anyone sell a descent aftermarket cam?

 

Well, sure you can do that and you'll end up with a better engine overall than the crate motor is, but that's going to be more money. If you want to go that route then maybe think about buying the Vortec L31 shortblock (since it's a one piece rear main style engine very similar to your L03 and is about the same price as the older Gen 1 crate motor short block). That then opens up the possibility of using a factory-style roller cam setup and then put in maybe an LT1 cam or something along those lines. The Vortec heads will also give you about a point more compression on top of either short block thanks to their smaller 64cc chambers (heads on the 250/290HP crate motor are 76cc).

But if you just want to run the base crate engine I'll just point out that though the cam is not large by performance standards, it's still considerably bigger than the stock "peanut" cam in the LO3. To the tune of about 15* more duration @ .050. It's a pickup truck/RV cam, basically, but still quite a bit hotter than the little weenie cam in the LO3.

 

I understand. Maybe I should just rebuild the LO3 and put a set of Vortec heads and a LT1 cam in it. that would make a bit more of a kick in the pants huh? Add my headers and exhaust, and maybe an upgraded TBI???

I guess I want to keep it as tame as possiable (to keep the MPG up) but also get lets say 250hp out of it, would that be possiable on the stock 305 (given a new rotating assembly, LT1 or LT4 camshaft, and some vortec heads and the hooker 2460's???

I thank everyone for all the responses thus far. I'm just deciding which way I want to go with this thing. If it comes down to it, I wil just leave the thing alone untill I cant stand it anymore.