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I need help figuring out why my whoever built my motor used 1.5 solid rockers on my 388 stroker with lt4 heads. I know they come with 1.6 rollers so I can't figure out why they would have installed 1.5's.
I know the block has been decked but I don't know exactly how much but from what I can tell the pistons are no more then .010 in the hole but I will have an exact number as soon as my straight edge shows up.
I was also told it has an lt4 hot cam but don't know for sure although everything else the guy I bought it from had told me had proven true.
it has speed pro L2491F pistons .060 over
Lt4 heads
Only thing i can think is for valve clearance but it all doesn't make sense because they had to spend extra money to get 1.5's because the lt1 heads that came off have different stud size so if anyone can come up with a reason as to why they May have done this please let me know.
Stamped and I thought about cost savings but this car had tons done to it cost savings doesn't seem to make sense over $200. Plus the 1.5's from the lt1 heads won't fit. I can say that my compression ratio with a zero deck is 13:1 but like I said in the original post I am waiting to find that out. Could it be too lost the dcr to run on pump gas? I ran it for 6 months on pump gas with no pings or issues? Idk I'm just confused about why that would be.
That's a great point. I will be honest with you I have owned this car for 15 years was only 15 when I bought it for 6000 and have put less then 2000 miles on it. I am actually a full time mechanic but haven't had the time to keep up with everything in the lt/ ls field. It had always been my baby ( other then my 3 kids) but haven't ever got the time or money to work on it until recently and the only reason I am fixing it at all is because I installed 1.6 rollers on it when I was 16 and didn't realize I had installed the non self aligning ( what Jegs told me my car took) and blew the head gaskets (young and dumb) I have slowly done things to it here and there but finally coming to an end and will have it done within a few months hopefully. Anyway I plan on running 1.6 rollers as long as valve clearance is OK but just wanted others input who have more knowledge of the lt motors.
IMO the best RR out there right now is the comp cams ultra pro magnum rockers. They are expensive, but you should never skimp on your valvetrain. I don't know how much you know, but just wanted to throw out there if you get non-self aligning rockers you will need hardened pushrods and guideplates.
I will be looking into those thank you for the input. I am a mechanic so I understand all the ins and outs of an engine and have rebuild plenty the only difference is they are factory and are cut and dry. The high performance world isn't something iv been into or had time to enjoy between work and family.
I would also like some recommendations on valve springs as well. The heads are at the machine shop now getting inspected and plan on upgrading the springs and having the stem seals replaced. Was considering the 918's but have heard mixed opinions.
Right now the rev limiter is set to 6400 but plan on having it dyno tuned and if need be raising that so i want something that can handle up to 7000+ without having to worry about float.
unfortunately i don't know for sure what cam is in it. I was told it has is an lt4 hot cam and so far everything the guy i bought it from told me has been true... so the lift with 1.6 rr would be 5.25.
Can i measure the height of the cam without removing it?
Dial indicator on a pushrod or lifter?
just checked out those springs and want to know what the angle of the retainer has to do with? Does it just depend on the valve or the retainer or both?
Are the seals the correct size for lt4 valve stems? Not sure if lt1 and lt4 valve stems are the same size?
Sorry if this is a dumb question but head work has always been sent to a machine shop were i work so i have never had to mess with any of that.
Get those Lunati springs. The valve stem seals are the right size "unless" the heads had them machined to .500 because of some weird spring they put in. Otherwise those Lunati springs are very good and what I have on my 383. If you are unsure about your heads just measure the width of the valve stem stud.
If you are spinning the motor higher than 5700, and you will, get NSA RR. The ones SSRRR mentioned Comp Ultra Pro Mags. Also step up to 7/16 ARP rocker studs for guide plates. Get the ISKY adjustable guide plates. LT1/4 Aluminum heads really dont do well with standard 1 piece guide plates. The Isky's allow adjustment and I have had them on for years
Trick Flow .080 thick wall chromoly (hardened) PR. You will need to measure since the heads & block have been decked. You will likely wind u with 7.100 or 7.150 length but you will need to measure.
DO NOT EVER GET COMP 918 VALVE SPRINGS
IMHO do not F around and cheap out on valve train. If you have the LT4 Hot Cam it really won't make much power above 6400 rpm. If you want a different cam contact Lloyd at Elliott Portworks. He is regarded the best...and also is the guy I bought my Lunati springs from although you can get them at the usual places
If you have stock metal LT1 valve covers you need to trim the intake side of the baffles. Easy
Hey ****** that's hilarious i was just about to message you because i saw you are running these springs ( on a previous post) and when i looked at you profile i saw you where looking at my post.
Anyways... so my question to you is what lifters do i need to run with this setup? I have roller lifters in it but have no idea what brand and want to use the best if I'm going to upgrade to the lunati's.
My other question is 153# seems high for a seat pressure is it not? Clearly you are running them but what is to high?
Also i have the heads at the machine shop now and need to get the parts either ordered or give him my list so he can get them ordered and installed. can anyone think of anything else i will need to get him to get this thing finished up?
And how long should these last before needing replaced?
Regarding the ISKY adjustables...you will likely need to grind some of them to allow them to come closer together on some cyl. to allow dead nuts L/R RR tip alignment to the valve stem. I did not weld the 2 1/2's together and I have over 40k mi on my build now with no issues
also just looked at my parts list and my RR studs were not with guide plate locators so the ones you list will work
Thank you a for all the help. I just got off the phone with llyod Elliott and he verified everything you said. I will be ordering those parts as soon as I get confirmation the heads are good.
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Rocker arms for 388 stroker 
