Ok, I would like to get a few opinions on this.

Right now I have a LG4 in my car. Engine mods include: Ported & polished 416 heads with Manley Race-Flo valves (1.94/1.5), Comp XE-262 cam, Comp springs, retainers, timing set, Comp 1.52 Magnum rockers, Edelbrock performer intake, SLP 1 5/8" headers, Holley Street Avenger 670 carb, DUI Distributor. Tranny is a Pro-Built 700r4 with SLP 2400 stall. Rear end is 3.73 with eaton posi.

I would love to do up a stout 350, but would rather put the cash towards getting the car painted. I have the option to pick up a 350 block for cheap.

What I was thinking was to throw together a 350 shortblock for hopefully under $1k and bolt the top end from the 305 onto this new shortblock. Then later on I can add bigger cam, better heads, etc. What does everyone think?

Also, any ideas how much of an improvement this might be over the 305?

Thanks for any input!

 

Your going to need some fair sized dish pistons or else your CR will be through the roof.

Other than that it should be bolt together and drive it.

 

CC the heads. Mine turned out to be 64cc, even though they had "58cc" cast into them. Others have reported 416's with larger than 58cc chambers, especially if unshrouded during the porting process.

Figure out deck height. My pistons turned out to be .026" down the hole. With .020" head gaskets, that's a nice .046 quinch height. With 10cc dish/valve relief .030" over pistons, static CR came out at 9.7:1. Runs on regular unleaded with no issues.

Also went from a Crane 2050 flat tappet hydraulic cam in the 305 to a ZZ4 roller in the 350. Otherwise, everything was swapped over from the 305 to the 350. The difference: 15.7 @ 90 mph with the 305, 14.4 @ 95 mph with the 350 (both at 5800' elevation - multiply the ET by .9276 & MPH by 1.0773 to get equivalent sea level #'s).

 

All the stuff from your 305 will work fine on a 350. It will have a lot more torque and a good bit more power. You'll think someone is pushing your car from behind compared to the 305's power. 50 extra cubes makes a big difference.