Guys
I’m after some feedback from anyone who has had experience with 400 small block and/or 427/454 big block Chevs in HQ-WB Holdens.
As a lot of you know I’ve got a HZ 1-tonner Overlander, which are standard with 308/TH400 and Dana60 rear diff. Mine has 4.10:1 diffs. I’m after specific experience with big cube Chevys in a HQ-WB. I’ve had 327 and 350’s in these models before, but am interested in the big displacement units. As the Overlander is NOT required to satisfy ADR27A, pollution requirements are only a carbon canister and 4.5% CO at idle. It also currently is dual fuel, and returns about 13mpg on LPG and about 15mpg on Pulp, so a big displacement engine won’t affect economy too badly.
The problem is the 308 is too small to be an adequate tow engine, especially in the Overlander. I’ve toyed with the idea of an injected 308, and also just a VN headed carbied engine as it runs on LPG 99% of the time. I’ve also got a shed full of 283,307,327 and 350 engines but a big cube, torque monster is ideal for what I need. The TH400 and Dana60 diff will easily handle the torque of a big block.
Using the 400 small block – I’ve heard that these are old steamers. I know if you don’t have a 4 or 5 core radiator, mechanical fan and shroud on a 350 in a HQ/WB they get too hot. Can anyone talk from experience whether 400’s are much worse?
A 427 or 454 – Anyone used one of these in a HQ-WB? How well do they fit, as in room wise? Cooling issues? I’ll probably use standard exhaust manifolds or 2nd hand extractors if I can find some. What about clearances to the power steering box? The engines I’m looking at are both STD deck height engines. The one most favoured at the moment is an early 1970’s Mercruiser 4-bolt 454 with external oil cooling.
Ive also been told that the radiatior to run with a SBC or BBC is to convert a HQ-HZ over to WB mounts and use a WB 4-core crossflow. Any comments?
