I have a bone stock 350 from a '78 Chevy. I believe this is the LM1 engine as I remember the suffix code decoded it as a 170 HP engine.

I was wondering what a ball park c.r. would be if I left the bottom end alone (stock pistons) but replaced the stock 882 heads with a set of Dart Iron Eagle 64 cc heads?

Also would a Comps cam XE274 cam work well with this stock bottom end/Iron Eagle heads combo?

8.5-9.0-1 compression...my son is using the xe274h in his 10-1 vortec headed 355...good low end,,,runs better than the Crane Energizer .470 lift,Lunati BM II .480 lift cam.

The XE-274 cam likes 10 to 1 compression or better. You'll also need a higher than stock stall and 355 gears or higher for this cam to be "happy". Depending on what your plans are for these variables, this may not be the cam for your set up.

Originally posted by Junkyard Dawg:
I have a bone stock 350 from a '78 Chevy. I believe this is the LM1 engine as I remember the suffix code decoded it as a 170 HP engine.

I was wondering what a ball park c.r. would be if I left the bottom end alone (stock pistons) but replaced the stock 882 heads with a set of Dart Iron Eagle 64 cc heads?

Also would a Comps cam XE274 cam work well with this stock bottom end/Iron Eagle heads combo? depending on the advetised compression ratio

if your motor has the 8.2 to 1 compression then the best you can get leaving the bottom end alone would be right around 9.7 to 1 thats using your 64 heads and a steel shim gasket...

if its the 8.5 then your looking at 10.16 w/heads and steel shim gasket.....

otherwise the thicker .039 gaskets are going to get you 9.22(8.2 motor) or 9.62 ( 8.5 motor)

Heck, It might even be a 7.9 to 1 motor like the 350 Mr. Goodwrench crate motor??

I just donno??

pdq67