five7kid

iTrader: (14)

I picked up an '87 LB9 that was taken out for its TPI by the previous owner but never used. In looking it over after getting it home, I discovered it had one proper "HO" 305 head and one standard 305 head. I haven't taken the heads off yet to compare other features such as valve size, but the intake ports are definately smaller on the standard head compared to the "correct" head.

Is there enough material in the standard casting to gasket match it? I would also gasket match the other head, like illustrated in the tech article, and attempt to make the two heads look like each other. I don't want to hit water and waste my time if there isn't enough material to do it, though.

My ultimate dream is to get S/R Torquer 305's, but my time has a larger balance than my budget.

------------------
82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

Jester

If you're right about what both heads are..there is a much bigger difference than just gesket matching. The runner design is totally different, and the non HO's are swirl port heads. Port all you want..you won't make up the difference.

five7kid

iTrader: (14)

I was at work when I wrote the question, and didn't have the casting numbers in front of me. They are:
14101081, which MorTec calls "87-95 305", and
14102187, called "87-91 305 1.84"/1.5" valves".

I may have assumed too much calling the 2187 "HO", but the ports almost match the gasket as is, so that's why I assumed it was the correct part. They both have similar carbon build-up, so appear to have been run about the same length of time. It's been out since '93, so was only 6 years old when pulled, although the guy who pulled it said he drove it home.

I have heard of swirlports, but not relative to engines that late of vintage. If I try to find a matching head, which one should I go with? In other words, is either an "HO" head, and which (if not both) is the swirlport? Looking closer down the port, I would guess the 2187 is swirlport, since it has a "wall" to one side of the valve at the guide, while the other doesn't.

Yeah, would prefer the S/R's. Or a 350. But, then's there's reality.

Jester

yeah..I can tell you that the 187's are swirl ports. I'm not familiar with the other one though..sorry.

ws6transam

AFAIK, There is no such thing as a "H.O." cylinder head. I'm curious to know if one head is for self-aligning rockers whereas the other is not?


------------------
Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
New best E/T! 14.039 at 100.82 MPH in 41 degree air at Stanton, Michigan.

Vader

57,

FYI, swirl ports hit the scene on four cylinders as early as 1984 (probably a little before.

Essentially, without getting into a deep technical quandry, they flow sufficiently for a small sedan with 13" wheels, but not much else. Head flow really fails the cylinders when the RPMs get above 3,000.

------------------
Later,
Vader
------------------
"Make Me Bad"
Adobe Acrobat Reader 4.0

five7kid

iTrader: (14)

Thanks for all the input. I may have used "HO" improperly. I was under the impression that there are different 305 heads, depending upon model: e.g., L69 has better heads than LG4; LB9 better than LG4, etc. The higher HP version would therefore be "HO". If wrong, I'll accept correction.

I don't see any evidence that either head is self-aligning, although again I'm going by what I've heard on these boards and not from first-hand exposure: "This head is self-aligning and that one isn't." Both have the different angle center intake manifold bolts and center bolt covers - THAT much I know.

The 081 has more gasket stuck to it (cover and intake) vs. the 187, so it very well may be that the 187 was the replaced head. All rockers, lifters, pushrods & springs look identical.

I'll have to decide what to do with the heads before I can get it running. The saga continues.

MRZ28HO

That only OEM 305 cylinder heads of preference are the carb'ed 305s (casting #416), which can be found on many LG4s (~'83-'87) and all L69s. JFYI

------------------
George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

five7kid

iTrader: (14)

Thanks. That was going to be my next question. I'm leaning toward using the carb on the LB9 shortblock & ZZ3 cam, obviously have a set of LG4 heads (need to check the casting numbers), and I think I have a line on a set of L69 heads. Could do the port work I was thinking on a couple of them, with new springs for the extra lift, and good grind/guide job. Roller cam, 9.5 compression; L69 on steroids.

Doubt I'll get Burk's ET's at this altitude, though...