Learn me: LT1 intake on early SBC

Bench building time!

Mmmk, today I was thinking about engine swaps for the camaro. Again. I dig the LT1 engines, and have thought of swapping one in before, however, their aftermarket is a bit thin (compared to regular small blocks.)

So here is my thoughts:

Some sort of 350 based engine, beit 383 or 355 or whatever.

LT1 intake

Converted to DIS using either LS1 or GM 3800 coils.

What I'm running into is the heads. Are LT1 heads any good? I know vortec heads probably won't work with the gen II intake. I know aftermarket LT1 heads exist, but I would like to keep this as grassroots as possible. My main goal is to boost power while avoiding the carb.

I'm not opposed to Gen III swaps, but them I'd have to change EVERYTHING, I think even with an LT1/LT4 intake I could re use all my accessories. Thus, saving $$$.

I was just thinking about this very engine last week and it's swapability. I ran into the same predicament, no AM support. But it does have a ton of parts you could backdate to the Gen I SBC. Or just bite the bullet for a LS and enjoy 40 more HP with less displacement.....

Oh and both the LT and LS need a cam swap before being called into action between the fenders....

Forgot to mention, car is a 1992 305 automatic, with TBI. And rattly ass T-tops. Wanting to build a strong street car, not concerned with chassis flex, or E.T.s

You can swap the LT1 intake onto an older SBC but there are a few things that need taken care of. You need to drill the intake and add a spacer for the distributor, you need to drill and tap the front coolant area and add a remote thermostat and radiator hose adapter, and you need to drill the center intake holes in the correct location. The ports do line up OK however. Search the internet for detail it is well documented. I am actually looking to go the other way. For my challenge car I am going to use an LT1 and adapt a carb intake to it. This is because I cannot budget the fuel system and injector upgrades needed for my power goals and keep the injection. If you decide to do this maybe I could trade you a LT1 intake for some challenge parts.

there is (or at least used to be) a company that sold converted LT1 intakes for use on old school small blocks. the pricing wasn't really that bad- like a couple hundred dollars if you had a core.

this was done as an upgrade for the TPI Vettes and F bodies before TPIS came out with their "mini ram" intake for those applications- which is also something to look out for.. a used mini ram intake on the e bays and craigslists would be a simple bolt on deal and give you all of the same benefits, with the added plus of having the water crossover and thermostat housing built into the intake casting and not requiring you to drill and tap any holes in the front face of your heads.

I remember the MiniRam.... It also showed a huge low and midrange torque loss whenever I saw it used in the rags, FWIW.

You don't have to drill the fron facing area of the heads. You can drill and tap the LT1 intake manifold over the coolant ports and screw in heater hose adapters but I agree that a mini ram would be a good way to go if you can find one at a reasonable price, just remember you will need the fuel lines and injectors, same goes for the LT1 intake get all the parts with it including the injectors and rails.

Ranger50 wrote: I remember the MiniRam.... It also showed a huge low and midrange torque loss whenever I saw it used in the rags, FWIW.

but it allowed the TPI motors to make power past 4500 rpm. the stock intake manifold setup is what really kept those engines from being great.

With the cost of LT1s as low as it is and since you are going with EFI, It would be just as easy and cheap to put the whole LT1 in your car. You can still convert it to DIS, plenty have done it, even though the opti-spark isn't a bad setup.

The accessory drive isn't that costly, probably cheaper than paying someone to modify a LT1 intake to work on a Gen 1 small block (LTs are Gen 2s). With some looking you could get an LT1 with the accessory drive setup already on it. Plus you would gain the advantage of reverse cooling and higher compression. Just my $0.02 worth.

LT1s are as cheap as 350s to buy now. Lt1 heads cant be used on a 350 as far as I know, but I think that the LT1 intake will bolt to vortec heads without being modified, while the others require redrilling the intake.

The Lt1 will not bolt to the vortec heads without modification the water passages need to be drilled along with the distributor hole. Even if you go DIS you still need a distributor stub or some other way of driving the oil pump.

an LT1 is NOT a cheap engine any more.. and neither is a regular gen 1 350.. it's actually reached the point where a 4.8 or 5.3 out of a 99 and newer truck is the cheap way to go..

go on www.car-part.com and do a search..

dmyntti wrote: The Lt1 will not bolt to the vortec heads without modification the water passages need to be drilled along with the distributor hole. Even if you go DIS you still need a distributor stub or some other way of driving the oil pump.

the LT1 came with a distributor stub to run the oil pump stock- all the crank and cam sensor functions are done by the optispark unit that is run off the front of the cam. it was quite an elegant design that had a few implementation issues.

If you count up all the accessories, mounts, etc, I can reuse what I already have. Whereas with a Gen III I've got to change everything. All things considered, I don't see it being a cheaper swap.

In reply to novaderrik:

Yes but the original poster wants to put an LT1 intake on an older small block so he won't have the oil pump drive or the optispark.

dmyntti wrote: In reply to novaderrik: Yes but the original poster wants to put an LT1 intake on an older small block so he won't have the oil pump drive or the optispark.

the LT1 intake can be machined to use a regular distributor, but you have to use a small diameter distributor to clear the plenum and i think the egr mounting point needs to be machined off and the passages welded shut, but it might be as simple as bolting on a blockoff plate..

by the time you do all the work on top of buying the intake, you will be miles ahead buying a bare holley stealth ram, get more torque, pick up some used LT1 or L98 injectors(i'll hook you up with a whole box if you want), and make or buy fuel rails.

i had one that was modded. you need to fill the center intake holes, machine away some material without going too deep to clear the new bolt hole location and drill them. then you need to do the water ports in the rear, and remove the EGR stuff to use a normal HEI distributor. then you get to machine the intake for a distributor, which is not straightforward. then on top of that you get to buy a remote thermostat housing and run everything through there. it gets to be an expensive proposition. better off buying a standard intake that can take injector ports and an intake elbow to bolt the TB to the carb hole. or the HSR.

IMHO way too much work. i ended up selling mine on here for $300 or so.