BrightRed93Z28

So I'm thinking of ways to freshen up my 1991 Corvette's performance. At first I was thinking about a converted LT1 intake and cam since many people have said that it really awakens the L98 and increases the range of power from 4500 to 6000 or so. After looking into it though, I found out that I would need to run a remote thermostat housing since there is no provision for one in the LT1 manifold. Lots of people thought that this kind of clutters up the engine bay, but I've seen pictures of conversions done and it doesn't look bad if time is taken in the placement of the remote housing. It's also the least expensive route. I then started researching the TPiS Miniram system with fuel rails and a cam, but that is quite expensive. The power gains of the Miniram over the LT1 intake don't really seem to justify the extra cost.

The more I thought about it though, would it be possible for me to swap a LT1 engine, but use a converted LT1 intake and keep my distributor? I'd essentially just remove the opti spark, get the block off plate with timing marks, and run the distributor. After checking out pictures of the two long blocks, it looks like most of the front accessories should bolt right up to the LT1 block / heads. Basically, would I be able to drop in a LT1 with modified intake, keep the waterpump / thermostat setup, and just run the other accessories on the stock L98 brackets? I would have to get another belt, but I'm sure I could find one that works. Anyone have any input or advice?

vetteoz

iTrader: (13)

No
Can't mix and match front drive because the GEN I water pump with the pulley to drive everything else does not fit GEN II LT1 block so you are stuck with all the LT1 Accessory drive
(must be the correct Vette only version with drv side top mount A/c , F/B body drive won't fit in a C4)


Only need a LT1 intake with a dist hole
Use the LT1 water pump ( see why above ) and 96 Vette radiator hoses
Large cap HEI won't fit LT1 intake unless you cut all the EGR boss off and weld up the holes
Once you have a reg dizzy in place you can use all your existing engine management wiring and ECM

vetteoz

iTrader: (13)

Keep which water pump ; the LT1 or the L98 ?

Jim85IROC

iTrader: (2)

Have you considered modding the TPI? My 91 had 1.6 rockers, TPIS base, runners & throttle body, a cam and a corresponding "phase 3" chip from Arizona Speed & Marine, and the car was significantly faster than a stock LT1. Plus the huge torque made it way more fun on my daily commute.

BrightRed93Z28

I would keep the LT1 water pump and find a belt to run the rest of the accessories. I looked at swapping the accessories to the Corvette LT1 accessories, but it would require moving pretty much all the components around. If I was to go that far, I might as well just swap the LQ4 in my garage into it and throw in a cam and FAST intake and call it a day, haha!

I have looked into it, but TPIS no longer sells their base or runners and those were the ones most people recommended. They do sell the Miniram, but that got me looking at the price and comparing it to the LT1 intake swap, and here I am......

FSTFBDY

iTrader: (33)

You can find used minirams for decent prices now. I use to convert LT1 intakes and never did like the clutter of the coolant lines and remote themo housing etc.

What about the HSR with the cut down top for the vettes? I forget who was offering a milled down plenum for the c4.

Jim85IROC

iTrader: (2)

There are other TPI options beyond TPIS. You can find used bases & runners, or the Edelbrock is still available. SLP runners are always around. You could always port your stock base, which will flow just as well as a TPIS/Accel/Edelbrock base.

There's always the Stealth Ram too. As far as I know, there are guys on Corvetteforum offering plenums that will fit under the stock hood, although they're a bit pricey.

EDIT: Looks like FSTFBDY said the same thing while I was typing!

I just wouldn't touch an LT1 with a ten foot pole. There's not nearly as much aftermarket support for them as for SBC and LSx platforms, and the efforts & costs associated with swapping the motor, harness, ECU, etc... it's just not worth it.

FSTFBDY

iTrader: (33)

Ahhh man , No LT1 love I like both of mine in sig.
Then again If I was to do it all over again a 408 lsx with my 78mm turbo would be a great setup in my 92 vert.

vetteoz

iTrader: (13)

I don't see it working because the belt under the no longer in existence L98 water pump pulley is a essential part of the TPI serp system
To run the belt from the AIR pump straight to the compressor would run through the middle of the intake accordian

novaderrik

if you're gonna swap anything, go with a newer LSx engine... it'll be a similar amount of work and expense with a far greater payoff in power and efficiency. plus if you get an all aluminum one, you will take a hundred or so pounds off the front of the car...

vetteoz

iTrader: (13)

My thoughts also
If I had a LSX sitting in the garage I would not even be thinking about a LT1 swap.
Just leap frog it completely to the latest generation engine

BrightRed93Z28

Oh the LSX swap has been thought about, but I really want to keep my ZF 6-speed and all the people who have done the swap with the ZF said that the aftermarket bell housing has to be machined in a certain fashion. I don't have any machine shops locally that I would trust to do it. I don't really want to switch to a T-56 when my ZF is just fine, although it would probably be easier to do so.

Jim85IROC

iTrader: (2)

I'd much rather deal with finding a machine shop I trust than having to deal with an LT1.