cookseyb

I'm in the process of re-building a 95 LT1 engine to go in my 94 SWB GMC truck. I have done all the machine stuff, heads trued, multi angle valve job, block decked, bored .030, honed with torque plates etc. I have ported ( gasket matched and smoothed) the heads, machined the stud boss down .325 and tapped for screw in studs and guide plates, opened up the pushrod holes to .500 for 1.6 Scorpion full roller rockers, turned down and the valve guide and enlarged the spring seats (Comp tool). I have the smaller valve stem seal. My question is how much and is it necessary to shorten the valve guide itself? I have a set of Comp springs that came with the 24502586 Hot Cam with retainers and locks. I have a "Test" spring in the mail, just wondering if anyone else ran across this. I have a mill so doing it isn't the issue just didn't want to screw the pooch...

BALLSS

so you "tapped" the heads for screw in studs....so are these iron heads?

you don't need to shorten the valve guide. For the hot cam springs you didn't need to cut the guides for the .500 seals but no big deal if you did. Gives you more spring options. Good you machined down the spring pockets as most aftermarket spring kits have a installed height of 1.800"

if these are the springs that come in the hot cam kit....you should consider others as those are for the lighter LT4 valves. They will start to float sooner than later using solid valves.

cookseyb

Sorry, the engine came from a Buick Roadmaster and they are iron heads, I kinda treated then like they were iron Vortecs. I'm not sure the springs are from the kit, they are about 1.500 at the base and that is why opened the spring pockets up. My son bought them prior to getting ill and passing away. I'm trying to resurrect this build for my grandson and am still learning about the LT1 platform. I'm an ol SBC guy

BALLSS

a good drop in spring kit for the iron head LT1 is the Crane 10309-1. Those did not require any machine work but what you have done will not be a problem other than they install at 1.750" so you would need to shim them.

If you don't know the history of the springs than pressure check them at the installed height and whatever height max lift will be with the cam you have. They may be just fine

cookseyb

I may change to a known spring, I think he bought these for Vortec heads. I have a set of LS2-LS6 yella springs, would they work with stock valves and this cam ( I could change it too)? I changed my LS2 build to Patriots and have these left over.I really haven't changed the spring height,I did them in the mill and only cut the spring bases till they cleaned up. I was planning on using the correct locator depending on the springs I finally choose. Thanks for your help. I will get the spring pressures verified if I use the Comp springs, they appear to be some kind of beehive and are painted blue. the info on the box was taped over and lost. I printed off the Comp spring spec sheet but was unable to match these to anything there.

BALLSS

if your Comp springs are single and taper smaller at the top and have a blue stripe, they are likely Comp 26918 "bee hive" springs

I had one break so don't have a good opinion on them.

cookseyb

I just ordered the Crane springs, I'll put those other springs in my left over parts pile to be used in a "spare Parts" 383 to go in the ranch 3/4 ton PU for pulling the Gooseneck, it's a 71 ol warhorse.. Only SOB I got that will start and run anytime I need it!

BALLSS

IIRC that Crane spring installed height is 1.750" so get a pack of shims and use a spring height measure tool on install

I assume the heads are still off the motor so installing springs should be a breeze

I use the Crane spring compressor # 99473-1. Bought it at least 15 years ago so it was much cheaper than it is now. You can do both I/E springs at the same time. The KB single spring compressor works also, much cheaper

cookseyb

I still have the valve spring tool that my Dad and his Brother bought in 1945 when they got their Sioux valve grinding machine. Which will still work by the way, but the modern cut seats etc are so much better. Working on 2nd head today, all I lack is machining and taping for studs etc.

cookseyb

Got the springs yesterday, look like quality parts. Thanks ****** for the recommendation! Any good recommendations for a ECM and stand alone harness builders to make this work in the 94 TBI truck? The trans is the same as the car was so that should simplify matters. Thanks in advance

shbox

The computer and harness from the donor car would be ideal.

cookseyb

The previous owner( my cousin) spun a rod in this engine and bought another good block which I re built for him as payment he gave me this long block and some accessories sooo I have to source a PCM and harness. My thinking is get a pre reworked harness and parts instead of scrounging in wrecking yards and then sending it to someone for rework.

BALLSS

As shbox posts, getting a donor harness. Basically any 94-95 B-body (OBD1) and the PCM.

IDK if a aftermarket from someone like FAST makes LT1/4L60E ECU

Obviously there will need to be "adjustments" to the harness to get it to work with the truck and pcm would need some programming, at least in the area of rear gears unless the donor PCM was from a B-body with the same gear ratio your truck has

My only LT1 transplant experience into another car is a 70 Nova...but I went Carb on the LT1 so no PCM

NewOrleansLT1

They do..

cookseyb

I think I have found a complete LT1 take out from a Buick Roadmaster for 400 bucks that includes harness and ECU! The picture shows an aluminum headed motor so the may not know what they have. Either way sounds like a good deal...