If I use this Camshaft, Hydraulic Roller LT4 Hotcam 24502586

and 1.6 rockers what springs do I need.
I have an L98 stock cast heads no porting is being done.

 

You could use the LT4 Hotcam springs that come in the kit!

16 Valve springs (12551483)

http://www.sdparts.com/product/12480...mshaftKit.aspx

Or you could do a search... LT4 cam has been discussed many, many times.

 

Actually no you can't, L98 heads are pretty much peaked at .480 lift. Anything past this beats the valve seals to death and you may even run into interferance with the actual valve guides. BTW there's more power to be had porting the heads with a stock cam than stabbing a big cam into a motor with stock heads. If you really want a cam for your L98 keep the lift around .450, duration around 210 and go with a set of generic ELGIN or PIONEER ".550" lift springs they should work out well.

 

If you're talking about putting that cam in your 305 TBI, then stop right there! That cam is way too big for a 305 TBI engine. The computer wont be able to handle it, and the heads are not designed for it. You need to stick to smaller cams that the TBI can handle, like a 206/210 with .470 lift or smaller.

 

no I am replacing the 305 with a 88 350tpi...

 

Heads have got to be machined for larger diameter springs as well. Might as well do screw in studs while your at it. Well while the heads are off might as well freshen them up, 5 angle, bowl blend, pocket port, new undercut valves, Eh, but then all that costs the same as decent heads.

 

and while you're at it, after you figure the costs, might as well go with some new-tech Vortech-style heads, take your pick, there's a lot to choose from...

I put the LT4 HOT cam in my '90 5.7L TPI. and upgraded the heads, intake, etc, while I was at it. I had some stone-age cast-iron back-in-the-day racing heads laying around, so they were "free-no-cost" to me. It is indeed a very fun daily driver, I'm happy. my only doubt is whether the 30lbs injectors are too big after reviewing the data logging analysis. shoulda stuck with stock injector size, woulda coulda shoulda... too much hassle to swap them out at this point.

If I had to do it over again (low budget), I might go with some cast-iron Vortech-type heads, and the corresponding Edelbrock TPI manifold base.

incidentally, because of the cam swap (& injector swap), it necessitated me learning how to set up my own chip. long story, painful but not too costly, a "very rewarding educational" experience.