Probably because a cast manifold doesn't require welding (lower per piece cost once the tooling cost is be recovered). So would expect tubing on a very low production requirement and cast for high.

Cast iron also has thicker walls so will deaden sound better and will add a bit of weight but would bet the driver is cost.

That said I wonder is the precision (or lack of it) is the reason for the ugly hole. Could be a fairly wide wariance in the collector attachment without any overlap errors.

Their Buick City rejects passed to Pontiac as seconds

I did not notice this on my 87 Delta spare engine but not sure I got a good look. Its not in the best place to see that side either plus it has a cap closing off the man. I check it out tomorow.

My opinion on the HO thing is this. It was sales propaganda. Because there is no low output engine. Thats why I hate to see people posting High output classifacation for an engine. It could mislead early learners that their engine is special. They are all the same. All LG2'* (1986) had 140 (irrevelent for Pontiac owners) All LG3-3'*(1987) had 150(possibly why the LG3 was called HO,it was an upgraded LG2) all LN3-C'* had 165. Doesnt matter if they were in a 98 Regency, Riviera, Cierra or whatever they were all the same. Anyone knowing positive infor on different outputs for various models with the same engine ,Im listening but I have never seen a low output or lets say non HO LG3-3 engine.

What engines did not have tubular manifolds ? Remember I never had a LN3-C. Pretty sure my 91 L27 has tubes. Ya keep making me second guessin That and I have to many engines, to many projects and too many years on my tired brain.

I know my 1990 Olds 88 Royale had cast iron exhaust, not tubular at all. So you can imagine my surprise that my 1990 Bonneville does. The 88 Royale was a vin "C" engine, I will look at the Bonney'* title later. Just as a side note...the Olds must have had differnt gearing because it seemed like it had more pull and always responded with a little more spirit. The Bonney, however, is no slouch at all

Visit your local AC-Delco dealer for a 40A-100 Remanufactured Transmission Catalog. Give the codes, ratios, for just about all trannys back to about 1969.

440T4/4T60 was available in 3.33 (mostly with 2.8, 3.1, & 3.3), 2.97, 2.84, & 2.73 finals.

Its called pitchin' . salesman opens the hood and the prospective buyer looks in. "Thats the high output engine" says the salesman. Prospect "hmm, can I get one with the normal engine" Salesman "this car here" and just moves over to the next car and saves the pitch for then next guy.

Wanna trade the 95 for the 93? Oh wait what was i thinking..... I'm glad i got a 93, cause that'* my favorite year, even if i woulda bought the 92 SSE.

I've got an 86 delta88 with a "3" code 3.8 ... it'* got tubular manifolds... anyone know if the aftermarket headers for the mid 90'* delta'* will fit????

No. If you read back through this very post you will find JR's3800 post about restrictions at rear manifold outlet. Other wize all that would help is welding up a rear manifold and crossover junction that would have longer tubes and less radical bends and junction. Look at a picture of TOG headers.

Just opened up the rear outlet on one and when you do it is evident that the header pipes were just stick into the log and welded - one sticks out almost an inch into the log.

That said the crossover pipe is 2" so I would expect the outlet would need at least that which means grinding the hole out as far as possible. Doubt that reflections from the outlet in the rear manifold are going to help anything.

Speaking of which the front manifold is pretty good. Suspect that just a new tuned rear manifold and new crossover pipe coming down to a collector about a foot further along would help everything except pulling the engine from the top.

Sure, just as soon as my wife comes back from being a tourist this week.