i started the adventure with my 87 TA thinking i was going to do the LT1 swap into the car. I have a lt1 complete with 4l60e and caprice harness. i sent the engine to the machine shop and had it redone and ended up needing new heads so the machine shop sold me aluminum heads. All said and done i have a freshly machined lt1 short block all the gaskets and such with aluminum heads. one potential problem i see already is one head is a 561 and the other is a 643, how much of a problem are they going to be being different. They both have already had valve job, new valves, performance springs, keepers etc. installed.
But now im starting to seriously look into whether i want build the lt1 and drop it in or look into an ls1 swap. i found an ls1 and tranny complete with no harness for about 1200 and may have a buyer for my lt1 but im not sure its worth ditching the LT1 after already having it machined to go to an LS platform. My thoughts for the LT1 were to get a cc503 with new lifters pushrods and 1.6rr. i was going to get a 2500-2800 stall and upgrade my rear to 3:73s. i was hoping to be at or just north of 350whp. So at this point im stuck trying to decide which way i want to go, part of me wants to go LS1 because of the great response to mods but from browsing the internet it looks like the LS1 is going to cost a lot more money to get into my car.

 

Honesty 1200 for a ls1 is good. I bought a 5.3 because I didn't want to drop 2000 for a ls1 so you're already ahead of the game. I'd say most of the cost was in motor and trans. Harness from pocket because I didn't want the hassle. Other than that it's really not all that bad. Personally I'd just sell the lt1 and grab the ls1.

 

I have had both. So I will give ya my opinion.

If you want to keep up with the times and have TONS of aftermarket support go LS now. I had a 355, then a 383 LT1 that went through NA/Spray/Turbo. Yes it was fun beating up on LS cars but when it came down to a freshen up I couldn't justify spending the money on old tech. I went LS. After I parted the car out I went to a C5 Corvette and loved it also. Only think I missed from the LT1 was the low end grunt compared to an LS

Jay

 

x2 on what Jay just said. Im moving on from a Boosted 383 LT1 to a H/C LS1 for now. Will get boosted next go round once its in and all bugs worked out.

 

I bought an LM7 (5.3) mainly due to cost, and I have 5 grand into the swap and I am finishing up now. Keep in mind I had absolutly nothing to start with and rebuilt the top end of the motor while I was there. This includes the trans aswell and all the incidentals.

An LT-1 swap is probably much less expensive as a swap all together. There is tons of aftermarket support for the LS1 family and it is well worth the cost in my opinion. It has tons of potential.

Just remember, done properly your engine swap could leave you with a brand new car

 

My biggest thing is I already spent the money on rebuilding the top and bottom end of the lt1 and just requires the cam and valve train installed to get the engine in the car. The rest of the money I have set aside can go to things like changing to 373s in the rear adding the stall converter and doing other to the car besides the engine swap. If I move to an ls swap all the money will go just to buying and refreshing the powertrain and leave nothing to actually getting it in the car and running and driving. So I'm worried if going ls is taking two steps back. I'm not looking for a high horsepower track car. This is a car that will be driven every once in a while and will probably never see a strip.

 

So wife made the decision for me. She said I have to keep the lt1 since we just spent the money rebuilding it. So I think I'm going to go with the hotcam since it seems to be more in the power band in looking for. My only question is what to do about the mix matched heads

 

Should be fine to bolt them on. The variance between the heads is probably similar as it is between ports on the same head. I think it would only matter if you were going to send the heads in to be ported. If you are having a set ported you want either 374 or 643 heads as they have the most meat. Advanced Induction requires one of those two castings for all of their CNC work I believe.

Or, you could try to source another head from somewhere to match the 643. 643, so if you are doing that, don't get another 561 head.

 

Yea I don't have any plans to have the heads ported. I just can't decided whether to go with the hotcam kit o r the cc503. I really done want to spin my engine up near the 6000rpm Mark and I'm thinking it's going to cost more to go with the 503 vs the hotcam kit for a 10-15whp difference

 

Might be able to get a semi-custom grind from Lloyd Elliot that performs much better but has the same driving characteristics.

But, on the other hand, if you run a straight up LT4 Hot-Cam or CC503 you can probably run a tune downloaded off the internet for one. For cam swaps that popular they are out there.

I had Lloyd's 226/232 cam and I was going to run that with stock heads. But then I got heads ported and moved to a 231/239 to take advantage of them.

I will tell you that the LT4 and CC503 are perfectly street friendly in manners. The exhaust note however is not sleeper status.

My GTA ran a 13.3 @ 103mph with the B-body LT1, which is smaller than the stock LT1 F-body cam. Video is in my sig.

 

I'm more looking at bang for buck. Figure by the time I buy the cc503 and 1.6rr the hotcam is probably cheaper for the kit. I'm also kind of iffy on my valve springs cause the engine builder said they are upgraded performance springs but didn't say what the specs were so I have no clue what these springs can handle, hence the hotcam comes with springs I at least know the specs on