The Evil Genius

Has anyone swapped out an LT1 for an older "normal" SBC? It seems given the plethora of parts and even crate motors, you can get a lot more motor for your money going back in time, and perhaps even up your reliability (read: optispark) overall. Thoughts?

mn_vette

There's one big thing that you loose out on though, fuel economy!

zr1fred

Go down to a parts store and look at an opti unit. It's the simplest distributer on the market, It's just in a bad location. The older technology offers (unless you are all out racing) a, worse reliability b, less power, c, less fuel economy. d. worse emissions. The LT-1 has, a, high lift roller cam, b, higher compression, c, better street heads (202's will actually hurt performance under 5000 rpm, and most of the engines you're talking about don't have them anyway).

Mr. Peabody

blasphemy

The Evil Genius

Alright alright. I was just askin!

86VX1

here go again, this is going to turn into a carb bashing thread so get your licks in early.

if you car is more of a track only car then go for it, have you seen how much it cost to replace the opti with an msd unit?

NitrousSam

It depends on what your goal really is. Remember a carb and an intake can create clearance issues and also air flow issues if the carb is practically touching the hood. I have a carb on my C4 but with an aftermarket cowl hood. The comment about horsepower being less with a carb is for non forced induction engine. Fuel economy is certainly not ideal with a carb but I am guessing your reason to switch has nothing to do with fuel economy. With all that said...we need to know what your goal is before we can help you further.

JD'S WHITE 93

You would have to be crazy to pull a HEALTHY LT1 and put in an older SBC for street use. The 94-96 LT1 cars have an electronic trans too so you would need something to make it shift with the carbed motor.
I THINK the converter lockup is all that is controlled by the computer on the early LT1 cars though which still would need to be addressed.

JD'S WHITE 93

A GM opti is less than $400.00 and can be changed in the driveway.
Not as big of a deal as it is made out to be, they last thousands and thousands of miles. My original unit lasted 12 years.

Road Agent

aboatguy

+2

chozen1

also look at msd opti with the fresh air and vacuum lines; plus user adjustable base timing screw that the stock units don't have (quick ques does anyone know which way advances timing clock wise or counter clockwise)

CentralCoaster

I drive thousands and thousands of miles per year. I want an ignition system that will last hundreds of thousands of miles. *ahem* HEI *ahem.


The very nature of this thread is going to **** off lots of LT1 owners, but just remember before you get antsy, he's modifying HIS car, not yours!

LTxDave

My 96 is on the original opti at 115k miles and my 95 (that I sold) was at 220k miles on the original opti. I had to replace the distributor gear on my 88 IROC with its TPI 5.7 at 70k miles. Nothing mechanical is perfect. The opti is a good unit as long as you don't do stupid things to it.

93 ragtop

IF you drive a lot, the opti will last. Its the ones that set, or make a lot of short runs that die. IMO I think it is a condensation problem.
But when they were used on police cars and taxi's they seem to last very well.
As far as "pissing off LT1 owners" the comments dont bother me, its just ironic how many of the comments come from people who never owned one. Not saying that applies to you, dont have any idea what cars you have owned, but never the less, it does apply to several on this board who give advise on the opti.

RWD_tech

dont the aftermarket optisparks fix the problems with the originals?

zr1fred

There is no real opti problem, other than a perceived problem. The ignition module, coil, and wires cause far more problems. Water pumps and washings cause 90% of the actual opti problems. Yeah condensation does cause some problems, but not nearly as many as you would be led to believe by this forum. It's kinda like the VATS, it's the first thing people blame, and usually the last thing it is.

bogus

I am beginning to wonder... where was I when they were handing out free crack to Forum members?

This is beyond stupid.

The LT1 equipped car is so much more modern and integrated, you would loose everything. If you want old school, by a C3 and be done with it.

neat

I'll go the other route and support the original poster. Given the option I'll take a conventional SBC over an LT1 everytime. I had a 1992 Corvette that I built a 383 for. It made good power on motor (380 RWHP / 380 RWTQ) and great power on nitrous (475 / 620), had AC, idled at 900, and drove great. Unfortunatelty, it had a whole plethora of LT1 problems. The hub spun on the crank, the opti, the steam pipe, etc... I eventually got sick of it sitting on jack stands, waiting for expensive replacement parts that I had to get from the dealer (Autozone doens't carry a waterpump drive coupling), and I sold it. I bought the 91 that I have now, and I couldn't be happier.

There are fewer parts available for the LT1 and the parts that are available cost more and typically make less power than their standard SBC counterparts.

The only positive thing about an LT1 is that they make 300 HP stock. If you are going to replace the heads and cam, in my opinion, you're better off with a conventional SBC. Your parts will be cheaper, you'll have quite literally 10 times the options in components, and it will probably make more power.

VR'92

You know the optispark is fine, just don't powerwash your engine.