[Mo]

Are the flow numbers based on 4.15 bore? Any dyno test on a factory block type build-up 400-474cid with the high ports? Seems like these are the heads to get for the stock block guys. Not so sure for the MR1 and IA2 blocks (N/A)since the Tiger flows 400. Hard to say since there is no price for the 370+ cfm high port that I could see.

Now, these heads on an IA2 or MR1 with about 18 lbs boost.....era..1200hp...era.."we need a bigger boat!!!" Thats what I'm talking about!

[RA462]

Tin Indian Performance's sight lists 700 hp and 628 ft lbs. on a 463 CID (stock block?). A 505 CID injun made 903 HP @7500 RPM!

[Mo]

Originally Posted by RA462

Tin Indian Performance's sight lists 700 hp and 628 ft lbs. on a 463 CID (stock block?).!

That's impressive. Only "problem" would be block strength when you spray it. Especially in a heavy car. On the flip side you can still make good power, go fast, with factory block and keep it affordable as long as it's in a lighter car.(Spotts FED, 7.20's, factory block, 1600#(+/-a few#)) I think for guys who have a prepped factory block these heads are the ticket but if I was starting from scratch I think the Tiger would be the way to go. JMHO.

[455firebird1969]

If you put the 56cc heads on a 4.185" flat top piston, zero decked 455, the compression would around 14/1 according to the Wallace calculator...

Can four head bolts per cylinder keep a gasket in place without failure?

Or, does it need to be O-ringed...