How much of a HP gain will i get going from a 305tbi to 350? Also if i decided to have someone else do the switch for me how much do you think it would cost (just exploring options) how about the gain between a 350tbi and 350 tpi?

 

If both engines are considered basically stock then you're going to gain 45 cid. A typical engine is around .7hp/cid so you can expect at least 32 more hp. The 350 has a larger bore than the 305 so the increase could be even greater. A 350hp 350 cid would be 1:1 but that isn't stock anymore.

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Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car and knocking on the SuperPro ET class
383 stroker (carbed) with double hump cast iron heads and pump gas
LS6 Big Block buildup now in progress

Best results before the 383 blew up
Best ET on a time slip: 11.857
Best corrected ET: 11.163
Best MPH on a time slip: 117.87
Best corrected MPH: 126.10
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car
91 454SS daily driver
95 Homebuilt Harley

[This message has been edited by Stephen 87 IROC (edited October 27, 2000).]