Builder

Hi All,

Does anyone know the length of the pushrods in a '96 LT1 from a B-Body?

Thanks!

groundpoundinlt1

iTrader: (57)

should be 7.2 for all lt1s...i may be wrong but im pretty sure

Builder

Thank you. Yes, as far as I can tell, that is correct. I just ordered the rods, seals, springs, retainers, clips, and 1.6 self-aligning 3/8" rockers (ProMag) for my '96 Impala SS. Was starting to feel a little float at around 5500 rpm. Hope it's not the lifters!

buffman

iTrader: (9)

I personally wouldn't be revving a b-body w/ stock shitty springs that high anyways. Most of the time they start developing valve float way under 5500rpm at around 4800rpm..

What kind of springs did you go with? Combination Motorsports has a good selection of springs and offers a good deal on the Pro Mag rockers.

Don't forget to mod your valve covers (bending brackets) before you try to reinstall the covers w/ the new rockers.

What install method are you going to use?

96capricemgr

iTrader: (1)

Yeah likely the springs since they are crap even when new and now they are 10 years old.

Builder

If you are a car guy, one of the nice things about living in Reno, Nevada is there's a Summit Racing distribution point here with a huge showroom (with complete cars in it). I was planning on going down there today to pick up the following in-stock CompCams parts:

1318-16 self-aligning 3/8" ProMags 1.6 (1.5 is stock in the Impala)
983-16 1.250 Ovate wire springs
751-16 1.240 steel retainer
613-16 Super Locks - w/o recess for lash cap 10° 11/32"
501-16 Valve Stem Oil Seals, O-Ring, Stock Guide, 11/32"
7608-16 Chevy Magnum push rods 265-400 + 90° V6 with OEM HYD roller cam

Except for the lifter ratio, these parts are directly from the Comp catalog for 94-96 Impala SS. Someone recommended the 26915-16 Beehive springs. Any comments on the above would be greatly appreciated.

I am sure many folks have used Combination Motorsports. They are probably a good company. However, I placed my order with them in December. Was told the order would ship the next day. I called the next day to see if it was shipped and was told it did. Two days later...no product. Was told they would ship the next day. Didn't ship. Cancelled order and vowed not to do business with Combination Motorsports. They killed the timeframe I had set aside over the new year's holiday.

96capricemgr

iTrader: (1)

If memory serves the SA promagnums are something like $320 from Summit, think they are closer to $260 from CM. There is a good thread on beehives for the iron heads on the www.impalassforum.com might doublecheck your PNs there. I wouldn't bother changing the pushrods at this time.

1.5 is the stock ratio on all gen1-2 sbcs as far as I know with one exeption being the LT4.

Builder

Well, okay. I will give CM another chance. It's hard to beat the savings.

My car has about 170k miles now. I read that the 94-95 push rods were hardened, but not the '96. I figure with the miles, I might as well replace them while I am in there. They are about $100 and I think that's cheap insurance. I wouldn't mind doing lifters too, but that's another xx hours.

Thanks, I will check the SS Forum as well.

buffman

iTrader: (9)

Yeah the 96s aren't hardened. Sounds like you'll have no problem in the higher rpms afterwards.

Matt

Builder

Also read that the knock sensors might be an issue. Any experience with 1.6 rockers effect on the KS? Are LT4 KS required?

Thanks,

buffman

iTrader: (9)

Yeah I would definately get a LT4KM if you're upgrading to roller rockers. Dal or ebay has them for less than $50.00 if memory serves me correctly.

Matt

96capricemgr

iTrader: (1)

NOT knock sensors knock module just wanted to clarify what Matt said since you two are talkjing about different parts. The knock sensors install in the block just above the oilpan rail. The knock module installs in the pcm. It is the module you need it acts sort of like a filter to help the pcm more accurately deturmine what is real knock and what is just engine noise, the roller rockers will make the engine a little more noisy so the LT4 knock module helps filter that out. Actually the whole reason the LT4 got a differnt module was because it came with roller rockers so really that module is made specifically to filter out rocker noise.

On the Comp ProMagnums some guys have complained they were loud if you find this too post back and we can try to guide you towards making sure they are adjusted best as they can be and then maybe help you pick an oil. Oil can have a HUGE effect on valvetrain noise and the single most popular oil for the LT1 isn't even a particularly good choice.

buffman

iTrader: (9)

opps I didn't even see he asked about the knock sensor instead of the module. Thanks for clarifying Dwayne.

Matt

Builder

Ohhh, I didn't know there were two parts to the knock detection. So, the LT4 KM is what I might need. Thanks for the heads-up. Dal is d'man!

I have been running Mobil-1 oil in her for about 80k miles. I can see how an oil could have acoustic properties. What oils do you think offer the best combination of attenuation and protection?

Also, I haven't seen a write-up on making the swap. I know I have to mod the valve covers. That's not too tough. I will be using the TDC method and I have a buddy who will lend me his LT1 spring compressor. What is the recommended procedure for installation? I suppose I can measure the number of turns it takes to remove the rocker stud bolt, but there must be an exact procedure for this.

Thanks, I really appreciate your comments.

96capricemgr

iTrader: (1)

On the oil the 5w-30 I am sure you are using is exactly what I was refering to. The guys that religiously send their oil out for analysis have shown that the specifically Mobil 1 5w-30 and 10w-30 are a bit thin for the LT1 and it prefers something a little thicker since you seem to like M1 I would recommend the 0w-40 or Truck and SUV 5w-40, those are better suited to this motor. Other brands are better in the 0w-30 or 5w-30 because they can run towards the thick end of the 30wt range(yes the 30wt is still a range and the M1s fall right at the bottom of the thin end). The oil affecting noise is somewhat unknown as to why one engine is quiet with this oil then the next is loud, I am sure it is complcated having to do with film thickness additives and a bunch of other technical stuff we gearheads can only begin to wonder about. For more oil related reading try http://theoildrop.server101.com/cgi/ultimatebb.cgi . Here is a great tech resource http://shbox.com/1/how_tos.html it is geared towards the f-body but the adjustment procedures are the same.

The TDC method is great for the spring swap, I have heard of some guys still insisting on using air but that is just making the job MUCH harder than needbe.

Builder

It's time to replace the plugs and wires also, so might as well get the TDC while the plugs are out. Another trick someone mentioned was to feed some soft rope into the sparkplug hole and bring the piston up. I thought that was cleaver. I checked the links. Great info. Thanks and I will report back when done.