Currently I own a 86 iroc with a 305 TPI and the head gasket blew along with some other issues. Instead of rebuilding my 305 I want to swap for a new 350 with EFI. I was looking on JEGS and found a 350 performance package that includes a new engine, remanufactured transmission, and transmission accessories that can be seen here:
http://www.jegs.com/i/Chevrolet-Perf...rentProductId=

It seems to be a great deal for $2400. I honestly don't need anything with too much horsepower and this engine will outperform a stock IROC 350 TPI. That's plenty enough for me as it will be daily driven. My question is, will adding an TPI system be easy to do with this engine and how expensive will it be to do? I want a TPI setup so I can stay true to IROC Camaros and it will give better mpg and be a smoother running engine overall. Second, would it be better for a local shop to build me a 350 instead? I'm trying to keep costs down and honestly want all new parts, even a new TPI setup. Last, how much horsepower will I gain over a carb setup on this engine? Any advice appreciated!

 

Another thought! Will my stock rear end hold up for this much power?

 

Tpi for fuel effect and easy cold starts, you can get southbays 22#hr injectors. send me a pm if you need programing. Rwhp on the engine will be close to 190 your rear diff will be fine. I'm not sure I would go from a 700r4 to a th350. You will need to get a install kit, crossmember/torque arm bracket. you can get the engine without the trans and use a 82-85 flexplate. The heads are junk for flow. IMO would get a l31 replacement, but depends on your budget and goal.

 

I found a set of L31 vortec SB Chevy heads for about 300 each. Would it be a significant improvement to switch to these heads? $600 for both is not bad and I wouldn't mind investing in them for better flow. I did some research on the th350 vs the 700r and I'm going to stay with a 700r4. Would it be cheaper to have mine rebuilt or just buy a remanufactured tranny? There is nothing wrong with mine currently but would like to have it completely rebuilt so there are no issues in the near future.

 

You might want to look at this and a cam change.
http://www.jegs.com/i/Chevrolet+Perf...30282/10002/-1
I'm not sure what the compression ratio of the other engine would be you would have to compare the head cc.
For the tranny I'm not sure probably have yours rebuilt.

 

Just got off the phone with a buddy of mine and he might just convince me to do a LS swap but a lot more expensive though. A lot to think about but he claims a built LS platform will yield about 400hp. He works at a shop that warrants all their work. I'm going down there Monday to speak with the owner and we'll see from there....

 

Your 305 has (or had) as much power as that 260 horse 350. How? Because your LB9 is rated "net" - running as-installed intake, full exhaust, accessories - and that crate engine is rated "gross" - headers, no muffler, velocity stack on carb, may use a different intake manifold and/or carb to get max HP and max torque numbers, etc. In other words, the crate HP is not "real world".

If you want a decent TPI crate engine, the L31 is a much better choice. It will require a different TPI base, but that's a small price to pay. But, by the time you get the base, cam, etc., you'll have spent almost as much as this would run you http://paceperformance.com/i-5146074...ck-engine.html (especially if you swap a roller cam et al into the L31 longblock). Your TPI base will bolt to that base ZZ4. It won't have 355 HP with stock TPI stuff, but it'll at least be much better than the 305 was.

And I agree about the TH700 to TH350 stuff. Huge downgrade that you will for sure regret.

About LS - man, that's quite a platform. But, it isn't straight-forward, so understand what you're getting into first. I'm running what is basically an LS6 clone, probably puts out in excess of 400 HP gross at the crank, has run sub-12 second quarter mile at sea level. I'm still running a (beefed-up) 10-bolt (admittedly mostly at our 5800' elevation, which cuts power a good bit).

 

BTW, one of the most difficult parts of the LS swap is emissions. I have collector plates on my '82, so as long as I don't let the registration lapse, I don't have to go through emissions inspection/test. You won't have that advantage, I assume.

 

Why are emissions a problem for an LS swap? I really like that ZZ4 350 with 355hp but I'm going to want to put in a different cam and if I'm going to pay that much for a 350 it better have the cam I want. This is why I'm considering an LS swap. I can get exactly the parts I want in the building process. The only problem with an LS swap for me is the additional parts I would have to buy such as a beefed up rear-end and transmission. Or I can have a 350 block built at my friends shop exactly how I want. It won't be as nice as an LS setup but I'll be able to use the same trans and rear-end if it's not too powerful.

 

The main aspect I want is good drivability. I will be driving the car A LOT and need a powerful engine that isn't too bad on gas. I know any v8 is not ideal for mpg but would like to have a powerful car with acceptable mpg.

 

You could build a 350 with whatever parts you desire, just like you could with an LS, you just can't get one as a crate. The ZZ4 is a good option, it gives a good balance of power and economy for a reasonable price but you will lose power with the TPI set up on top of it because it is set up for a carb.

I went with an ATK L31 replacement short block, bought a set of modified vortec heads that are cut for larger valve springs, had screw in studs, and light porting, went with the LT4 hot cam kit (I don't recommend this), and a Holley Stealth ram. It makes good power and gets somewhere between 18-22 MPG typically on the highway.

 

I'm actually leaning away from the tuned port injection setup now. I definitely want electronic fuel injection and not a carb.

 

With an LS swap, you have to use some sort of package the factory certified (or with certified aftermarket parts in that system). That means not only do you need the LS EFI system, you have to have the cats, EGR (if the system you're mimicking had EGR - some didn't), A.I.R, and EVAP.

For LS systems, the EVAP is controlled by the computer, so you need that entire system in the car. Part of the EVAP control is fuel tank pressure, so the best way to accomplish it is to use a factory fuel tank that has the system installed - typically a 4th gen LS1 plastic tank. The fuel gauge is part of that sensing system, and that signal goes directly to the PCM - for a 4th gen f-body, the fuel gauge is a serial output signal from the PCM, which is not compatible with a 3rd gen fuel gauge (or the typical aftermarket fuel gauge). So, the solution there so you have a fuel gauge is to swap in the entire 4th gen instrument panel (which usually means the entire dash).

So, it's not impossible, but it is very involved.

Or, you could get this http://paceperformance.com/i-6255562...nsmission.html

How's your budget?

As for aftermarket TPI manifolds on a ZZ4, the "best" one is the Holley Stealth Ram. Unfortunately, it isn't emissions-certified. The Accel Super Ram is, but it isn't as good as the Stealth Ram. The Edelbrock TPI base and somebody's aftermarket runners with a ported plenum will be emissions-legal and give decent power - way above what your LB9 had. For your stated goals, I don't see a need to change the ZZ4 cam.

You could also do a LT1, but you'll have the same emissions issues as with a LS.

Since you said this will be a daily driver, it really comes down to budget. From what I'm seeing, I'd say build a 350 and keep TPI, or get a "good" 350 crate and keep TPI. With the TPI "improved", of course.

 

I didn't know the LS swap was so involved! I'm probably just going to do a 350 with injection now. What about this for a crate engine? It's the 350 ram jet. It says the manifold and plenum is 9.75 in tall. Will that fit under my iroc hood?

 

http://www.jegs.com/p/Chevrolet-Perf...49882/10002/-1

 

It will fit under the hood, but it is not emissions certified. You could use the TPI operating system, but the intake doesn't have provision for EGR.

Back in the late 90's, a former Colorado resident/fellow 3rd gen enthusiast put a ZZ4 crate engine into his '90 RS, converted it to TPI, and got it through emissions as a Corvette engine/system ('86-1/2 to '91 Vettes used aluminum heads like the ZZ4 does, did not use EGR in the TPI system). Since Envirotest doesn't get all that into the visual, you could most likely swap in the ZZ4 engine using your current TPI stuff (or go with aftermarket base & runners to improve power - no emissions issues with them), and get it through as long as you have the A.I.R. system and a cat. It should sniff clean enough, even for NOx, to pass. The ZZ4 cam cools off the intake charge sufficiently to keep NOx down. Leave the EGR valve and stuff on there, it just won't do anything.

 

read this post if you are interested in an upgrade I like the LT1's and they are pretty impressive. https://www.thirdgen.org/forums/engi...otor-shot.html

I'm not to far away from you, Wichita Ks area and I believe that you could possibly make your emissions - ??? using your stock ECU???

 

That seems like a great price for a ZZ4 Long Block! Do you know if the engine is a 1 piece rear main seal? (It says Internal Balance) And are those the old school type 58cc Corvette Heads?