CELEBRATING 20 YEARS!

Actually it was meant to be a friendly jab at both you and Travis, didn't mean to get anyone upset. LS guys do tend to hijack SBC threads on car forums which is not always helpful which the linked meme refers to. The LS fan over enthusiasm can come across as annoying wither intentional or not. For a 350 I would rather have 350 heads too, I would just get a Vortec crate and be done.

Which 305 heads did you port out? There were several different 305 castings with some better than others. The swirl ports being the worst of the lot which thankfully MCSSs do not have. 305 heads should have larger valves installed for 350 use, did you install larger 1.94 valves? Stock 1.84 valves on 416 heads are sized for filling 305 cylinder volume, not 350 cylinder volume.

416 stock flow numbers https://www.thirdgen.org/forums/tech-general-engine/591429-stock-416-head-flow.html

L98 stock flow numbers https://www.corvetteforum.com/forum...um-head-flow-numbers.html#post1545504940

416 heads can be ported out to 240 / 190 which beats stock vortecs. https://www.thirdgen.org/forums/tech-general-engine/308973-vortec-heads-vs-my.html#post2429844

Granted Vortec heads are a better starting point for porting.

Frankly if a person wants true modern performance, then buy a modern car and be happy. A 40 year old granny mobile is not the best basis for a modern hotrod, or even a retro tech hotrod. IMHO, modern tech is overrated and has its shares of drawbacks like aforementioned DBW controls, yuck.

Its possible for a car to have an incorrect emission label installed. Previous owners can do weird stuff to these cars or hire mechanics that do likewise.

Rick, the CCC is pretty simple to work on. With Qjets, the throttle blade position at idle can affect other areas. Too far closed causes an off idle bog, too far open and you get nozzle drip. Moreover, the idle mixture needles in the throttle body affect both idle and off idle mixtures while the idle air bleed valve in the airhorn affects just the base idle mixture. Set the idle mixture needles to 3 and 3/8 turns from lightly seated, then adjust the air bleed for correct dwell. Base ignition timing also affects idle quality.

As for top end power issues, check your fuel flow and secondary airvane tension adjustment. As I said before, Montes got restrictive single snorkel aircleaners to knock their power down by 10 HP so as not to upstage Camaros which got higher flowing twin snorkel aircleaners. My police packaged Crown Vic has 11 extra HP due to having a higher flowing aircleaner, air intake restrictions can really affect top end power.

Hi Buick,

OK - the clarification helped. The LS plug was not to annoy but to suggest a better and probably cheaper path to EFI delivery with more power, better economy, and modern reliability.

The heads I ported were fresh Corvette 350 aluminum L98 heads ordered from GM around 1988 as I recall. 1.94"/1.50". Magnesium valve covers. I did the usual mods everyone does: enlarge/smooth the bowl, narrow/streamline the valveguide boss, widen the intake port at the pushrod pinch-point. Frankly, I was surprised the flow came up as much as it did for so little work; too bad the original numbers are long gone in some forgotten notebook somewhere. I also remember the exhaust side came up fractionally even more, but again, too much time has passed for a clear recollection.

About modern performance in an old car: I believe in having them both. If I could take an MCSS body and wrap it around a Tesla, I'd do it in a heartbeat. With the A/G body, GM basically did as little as they could as quickly and as cheaply as they could to recover from the Middle East oil crisis. The goal at the time was an engine that would last only 75,000 miles, and performance was barely an afterthought. So no, I have no qualms whatsoever about trashing the dull engineering in that car and bringing it into the 2020s. And sorry, Buick, but I couldn't possibly disagree with you more about modern tech being overrated. In fact, what I see here is more the opposite: it's the old tech that's overrated.

But at the same time, I can see and respect Rick's desire to stay with more period-correct technology.

I also could not disagree more with you that older tech is as bad as you claim. My 305 has 100k on the clock and still has excellent compression readings with little deviation between the readings. Before I swapped it into the Regal I had to pull a head to get a broken exhaust manifold bolt off and the cylinders on that bank still had hone marks and no ridge. Its not uncommon for 305s to last 300k. I also have a 70 year old tractor with original engine internals that runs like it was new.

One advantage I will give to modern tech is that it is often more forgiving of neglect than older tech. Then again new tech tuning is locked behind hefty software paywalls, requires a degree in electronics, as well as various obnoxious nanny and eco tech like DBW throttle to contend with. Overall, modern tech is far less servicable for hobbyists on purpose and it gets worse the newer and more modern it is. Most LS guys farm out most of the work rather than perform it themselves such as wiring and tuning but some car owners see that as a good thing.

But this is hijacking the OP's thread, we will just have to agree to disagree.

Not a hijack, great discussion.
Seen some LS jobs that really shined, some pretty sloppy.
IMHO a car is only a virgin once, after that its never the same as it rolled off the line.
Sure it matters to me and not to others, I get it.
Some gotta go 150 mph some are happy at half that.
The long term problem is hop ups are unless you upgrade the whole drive train and front end, its gonna let you down as things break that weren't designed for it.
When I pop the hood on a 40-50 year old car and see either a untouched original or meticulously restored engine its a turn on tbh.
We're not even touching on keeping the numbers correct, and that alone down the road WILL matter to purists.
I have 3 cars that are all original and near complete with this 69 442.
Is that a car that would have more or less value with an LS?
What would a buyer want more?
https://www.facebook.com/photo/?fbid=10221915165362295&set=a.10220823234824714

This 1971 MC was a complete frame off.
The engine bay was absolutely perfect in every detail, no runs, no drips no errors or grease.
What would you want more, that or one that had an LS slammed in there?
https://www.facebook.com/photo.php?...t=pb.1053952666.-2207520000..&type=3

I'd take the 71 MC as it is!

Hi Rick - That 1971 is a beauty for sure! Glad you took the LS subtopic in the light it was intended. Buick - well, nah - forget it. You didn't take the LS subtopic in the light it was intended. We've been around this block at least a hundred times in different threads. Enjoy your world. Peace.

I do understand the reasons.
The LS is a strong engine costing far less than building a stroker or charging which will shorten the engines life.
If the original engine was puked that might be my direction also.

So interestingly enough with the scan tool hooked up I am getting 3 codes.
A 24, 36 and 42.
Also found the data stream pretty complete but found the engine temp sensor low, like 85-95 when the analog is reading 200.
I am getting map voltage reading changes, so its functioning it appears.
In kinda deep on another car atm, but feeling pretty good about the ccc system now, thanks for leading me on here guys.
Baby steps, but its all making a little more sense to me now vs before.

Rick - any chance the scanner is reading temp in centigrade? 200F is 93C?

Have to look again I guess, its a possibility.
The scanner is totally new to me at this point.
tx

Temp is in C yes, hard to read while driving lol.
Anyway Code 42 pointing at a bad distributor module, need to have it tested I guess.
It does go into closed loop, so the ECU is in control.

Internet saying code 36 is a mass air flow sensor problem, but thought that started with TPI and I don't see one on this engine unless its hidden.
Pretty straight forward induction through a normal air cleaner, no extra plumbing or wiring.
Another 36 is a crank position sensor which this doesn't have in the traditional SBC location behind balancer.
The other one was a 4T60E shifting error and it has a 200R trans.
Anybody followed this string before?

This is from my 88 manual so might not be the same for code 42 troubleshooting. Also there is no code 36 on a 88 monte so I wouldn't think it would be on any others. The manuals really help and any one that owns a monte should have one, they are invaulable.

Thanks Brent, I did get the manuals but car is at work manuals were at home.
There is definitely some control switching going on with the ecu.
Sometimes on cold start I get a service light and different idle speed.
Key off and on and lights out and the engine is running smoothly again.
I have not seen it go open loop where the controls are fixed once at temp.
I will follow this flow chart to the letter to figure this out and report.
Thanks for the assist
r